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Viruses and the Mac FAQ

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Archive-name: computer-virus/macintosh-faq
Posting-Frequency: Fortnightly
Last-modified: Fri, 1 Jan 2000 19:14 GMT
Copyright: Copyright 1996-2000 by David Harley and contributors
Maintainer: David Harley <>

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Viruses and the Macintosh 
by David Harley 
Version 1.6b: 7th January 2000 

  Significant changes from the previous version are flagged with + 
  symbols in the first two columns at the start of the relevant line 
  or section. Amendments of minor grammatical or syntactical errors 
  are not flagged unless they affect factual accuracy or clarity. 

  Sections tagged with [DH] or [SL] are hangovers from the time when 
  maintenance of the FAQ was shared between David Harley and Susan Lesch, 
  and usually denote personal opinions the originator didn't feel the other 
  maintainer should be held responsible for. Untagged sections using 
  the first person are usually attributable to David Harley. 

  This version of the FAQ primarily reflects my involvement in setting 
  up an information resource at ICSA. This will affect the availability 
  of the FAQ. The next version will require extensive URL checking, 
  and will probably introduce major formatting changes. 

  David Harley 

Table of Contents 

  1.0  Copyright Notice 
  2.0  Preface 
  3.0  Availability of this FAQ 
  4.0  Mission Statement 
  5.0  Where to get further information 
     5.1  Computer Virus FAQs 
     5.2  EICAR 
     5.3  "Robert Slade's Guide to Computer Viruses" 
     5.4  Web sites 
     5.5  Virus Bulletin 
     5.6  Macro virus information resources 
     5.7  Other resources 
  6.0  How many viruses affect the Macintosh? 
  7.0  What viruses can affect Mac users? 
     7.1  Mac-specific system and file infectors 
     7.2  HyperCard Infectors 
     7.3  Mac Trojan Horses 
     7.4  Macro viruses, trojans, variants 
     7.5  Other Operating Systems, emulation on a Mac 
     7.6  AutoStart 9805 Worms 
     7.7  Esperanto.4733 
  8.0  What's the best antivirus package for the Macintosh? 
     8.1  Microsoft's Protection Tools 
     8.2  Disinfectant Retired 
     8.3  Demo Software 
     8.4  Other freeware/shareware packages 
     8.5  Commercial Packages 
     8.6  Contact Details 
  9.0  Welcome Datacomp 
  10.0  Hoaxes and myths 
     10.1  Good Times virus 
     10.2  Modems and Hardware viruses 
     10.3  Email viruses 
     10.4  JPEG/GIF viruses 
     10.5  Hoaxes Help 
  11.0  Glossary 
  12.0  General Reference Section 
     12.1  Mac Newsgroups 
     12.2  References and Publications 
  13.0  Mac Troubleshooting 

1.0  Copyright Notice 

  Copyright on this document remains with the author(s), and all 
  rights are reserved. However, it may be freely distributed and 
  quoted - accurately, and with due credit. 

  It may not be reproduced for profit or distributed in part or as a 
  whole with any product for which a charge is made, except with the 
  prior permission of the copyright holder(s). To obtain such 
  permission, please contact the maintainer of the FAQ. 

  Primary author and maintainer of this document is David Harley, 
  Comments and additional material have been received with gratitude 
  from Ronnie Sutherland, Henri Delger, Mike Groh and Eugene Spafford. 
  Thanks to Bruce Burrell, Michael Wright, Peter Gersmann, David Miller, 
  Ladd Van Tol, Eric Hildum, Jeremy Goldman, Kevin White, Bill 
  Jackson, Robert Slade, Robin Dover, and John Norstad for their 
  comments and suggestions. Special thanks to Susan Lesch for her 
  contributions, editing, and maintenance chores as co-maintainer. 

2.0  Preface 

  This document is intended to help individuals with computer 
  virus-related problems and queries, and clarify the issue 
  of computer viruses on Macintosh platforms. It should *not* be 
  regarded as being in any sense authoritative, and has no legal 
  standing. The authors accept no responsibility for errors or 
  omissions, or for any ill effects resulting from the use of any 
  information contained in this document. 

  Corrections and additional material are welcome, especially if 
  kept polite.... Contributions will, if incorporated, remain the 
  copyright of the contributor, and credited accordingly within 
  the FAQ. 

  David Harley <> 

3.0  Availability of this FAQ 

++The reference site for this FAQ is now However, my own
  site at <> will be the 
  first place new versions will be posted.

  It's also available from Henri Delger's Prodigy Anti-Virus Center 
  file library, as is the alt.comp.virus FAQ. It will probably be available 
  shortly from <> 

  There are HTML versions at: 

  I have no control over the content of these sites, and can't guarantee 
  that they're up-to-date. 

4.0  Mission Statement 

  This document is a little different to the alt.comp.virus FAQ, 
  which David Harley also co-maintains (at time of writing). It is 
  concerned with one platform only, and though it deals with the 
  Macintosh platform at more length than the alt.comp.virus FAQ can 
  be expected to, it is a great deal shorter. Nor is there the same 
  degree of urgency about the Mac virus field, though the risk 
  element may be somewhat underestimated in general, at present. This 
  FAQ originated from a concern over the spread of macro viruses, a 
  theme that is taken up below. Since questions about Macs and 
  viruses tend to appear more often in the Mac groups than 
  alt.comp.virus or Virus-L, distribution of this FAQ is wider. 

5.0  Where to get further information 

5.1  Computer Virus FAQs 
  Computer Virus FAQ for New Users 
  A mainly non-Mac virus FAQ posted to news.newusers.questions, 
  alt.newbie, alt.newbies, alt.answers, and news.answers. 

  alt.comp.virus FAQ 
  This is posted to alt.comp.virus approximately fortnightly. It 
  includes a document that summarizes and gives contact information 
  for a number of other virus-related FAQs; (not much Mac-specific 
  material). The latest version is available from: 
  <> but the reference version will 
  eventually be the one at (page currently under construction). 

  VIRUS-L/comp.virus FAQ 
  The Virus-L/comp.virus FAQ (also fairly low on Mac-specific 
  information) is regularly posted to the comp.virus newsgroup 
  (version 2.0 at time of writing). This FAQ is very long and very 
  thorough. The document is subject to revision, so the file name may 
  change. The latest version may be found at: 

5.2  EICAR 
++Dr Solomon's Anti-Virus Toolkit, Virex, and NAV (Norton AntiVirus 
  for Macintosh) now support the EICAR test. This article by 
  Paul Ducklin of Sophos explains the EICAR test file: 
  <>. [SL] 

5.3  "Robert Slade's Guide to Computer Viruses" 
  The disk included with the 2nd Edition of this excellent general 
  resource includes most of the information available at the 
  University of Hamburg (see 5.5). The book also contains a 
  reasonable quantity of Mac-friendly information. The disk includes 
  a copy of Disinfectant 3.6, which is now out-of-date -- 3.7.1 is 
  the latest and final release. For more information about this book: 
  <> [Springer] 

++Very few books primarily about computer viruses deal at any length 
  with Mac viruses (I can't think of one, at present). Some general 
  books on the Mac touch on the subject, but none I can think of add 
  anything useful. Some of the "Totally Witless User's Guide 
  to......." books dealing with security in general include 
  information on PC -and- Mac viruses. Unfortunately, the quality of 
  virus-related information in such publications is generally low, and 
  there are few or no books on computer viruses in general which are 
  both recent -and- accurate. 

5.4  Web sites 
  Many major vendors have a virus information database online on 
  their Web sites. Symantec (, Network Associates 
  (, Sophos ( and Dr. Solomon's 
  ( include Macintosh virus information. 

  Precise URLs tend to come and go, but you might like to try the 

  Symantec Antivirus Research Center 
  Virus Encyclopedia based on Project VGrep: huge, and now has a 
  search engine. Probably the most complete [SL]. But not always the 
  most accurate [DH]. ;-) 

  Network Associates, formerly McAfee Associates: 
  Virus Information Library 
  Macintosh Viruses 

  Sophos Plc 
  <> "Macintosh Virus Desriptions" 
  Part of work in progress by Ken Dunham 
+ <> (new domain name) 

  Mac Virus 
++[Site closed 5th September 1999] 

  Dr Solomon's "Mac Viral Zoo" 
  Starting to go out of date 

++Keep watching <> 

5.5  Virus Bulletin 
  The expensive (but, for the professional, essential) periodical 
  Virus Bulletin includes Mac-specific information from time to time. 
  However, if you have no interest in PC issues, you probably won't 
  consider it worth the expense. 

  Virus Bulletin Ltd 
  The Pentagon 
  OX14 3YP 

  +44 1235 555139 

  The proceedings of the 1997 Virus Bulletin conference contained a 
  paper by David Harley which significantly expands on many of the 
  issues addressed in this FAQ. Contact Virus Bulletin for further 
  information on the annual conference and on obtaining the 
  proceedings. The paper can also be found (by permission of Virus 
  Bulletin) at the author's website <> 
    and at <> 

5.6  Macro virus information resources 
++University of Hamburg Virus Test Center Macro Virus List is the 
  definitive listing. All known macro viruses, some only found in 
  research labs, some in the wild. Doesn't include information on 
  individual viruses apart from name and platform, and somewhat 
  irregularly maintained. 

  Other Sources: 
  <> (under Virus Information) 

  [The following absolute URLs may change: such is the way of Web 
  administrators..... If you get an error message, try the first part 
  of the URL, e.g. <> and drill down from there.] 

  Dr Solomon's Software Ltd. 

  Central Command 

  Network Associates 

  Data Fellows 

++Richard Martin put together an FAQ on the subject of Word viruses. 
  It's well out-of-date, though, and was always inaccurate in some 
++N.B.This URL may be out of date. There is a copy of what I believe 
  to be the last released version at SherpaSoft: 

5.7  Other resources 

  There are excellent pages on HyperCard viruses at HyperActive 
  Software. There is information on HyperCard infectors, a link to 
  Bill Swagerty's free Vaccine utility for detecting and cleaning 
  them, a note on false positives reported by commercial software, 
  inoculation, and a free HyperCard virus detection service. 

  The CIAC virus database includes entries for PC, Macintosh, and a 
  number of other platforms. The Macintosh section also includes a 
  number of joke programs and one or two apparent hoaxes. 

  Virus Test Center, Hamburg: AntiVirus Catalog/CARObase early work 
  These links may be out-of-date: if they don't work, try 

  Last we checked [03-Sep-97], these sites probably need updating, 
  though some older files do have historical value. Info-Mac mirrors 
  have Macintosh information, but includes some outdated virus 
  information and software at this writing; still, always worth a 

  Also of interest, again sometimes outdated: 

  Kevin Harris's Virus Reference was last updated 31-Aug-95. This 
  HyperCard stack requires HyperCard 2.1 or later. 

6.0  How many viruses affect the Macintosh? 

  There are around 40 Mac-specific viruses and related threats. 

++Mac users with Word 6 or versions of Word/Excel supporting Visual Basic 
  for Applications, however, are vulnerable to infection by macro 
  viruses which are specific to these applications. Indeed, these
  viruses can, potentially, infect other files on any hardware 
  platform supporting these versions of these applications. I don't 
  know of a macro virus with a Mac-specific payload that actually 
  works at present, but such a payload is entirely possible. 
++Office 98 applications are in principle vulnerable to most of the 
  threats to which Office 97 applications are vulnerable. I'll return 
  to this subject when and if time allows. [DH] 

  Word Mac version 5.1 and below do not support WordBasic, and are 
  not, therefore, vulnerable to direct infection. Not only do these 
  versions not only understand embedded macros, but they can't read 
  the Word 6 file format unaided. There is, however, at least one 
  freeware utility which allows Word 5.x users to read Word 6 files. 
  This will not support execution of Word 6 (or WinWord 2) macros in 
  Word 5.x, so I would not expect either an infection routine or a 
  payload routine to be able to execute within this application. 

  However, Word 5.x users may contribute indirectly to the spread of 
  infected files across platforms and systems, since it is perfectly 
  possible for a user whose own system is uninfectable to act as a 
  conduit for the transmission of infected documents, whether or not 
  s/he reads it personally. 

  Files infected with a PC-specific file virus (this excludes macro 
  viruses) can only execute on a Macintosh running DOS or DOS/Windows 
  emulation, if then. They can, of course, spread across platforms 
  simply by copying infected files from one system to another. 

  DOS diskettes infected with a boot sector virus can be read on a 
  Mac with Apple File Exchange, PC Exchange, DOS Mounter etc. without 
  (normally) risk to the Mac. However, leaving such an infected disk 
  in the drive while booting an emulator such as SoftPC can mean that 
  the virus attempts to infect the logical PC drive with 
  unpredictable results. 

  I am aware of at least one instance of a Mac diskette which, when 
  read on a PC running a utility for reading Mac-formatted disks 
  after being infected with a boot-sector infector, became unreadable 
  as a consequence of the boot track infection. 

  Some Mac viruses may damage files on Sun systems running MAE or 

7.0  What viruses can affect Mac users? 

  Not all variants are listed here. It was originally intended to 
  reference all the major variants at least by name eventually, but 
  since the information is of academic interest at best to most users 
  (and available elsewhere anyway), it's no longer considered a 
  priority. The main problem affecting Mac users nowadays is the 
  spread of macro viruses, and I can't possibly find time to 
  catalogue them individually, so they are only considered generally. 
  Native Mac viruses are rather rarely seen nowadays, and most people 
  don't need to know about them in detail -- in fact, what they need 
  most is to know that their favoured antivirus software will deal 
  with them. Note that I'm not primarily in the business of hands-on 
  virus analysis, and cannot accept responsibility for descriptive errors 
  based on third-party information. [DH] 

  The following varieties are listed below: 
  7.1  Mac-specific system and file infectors 
  7.2  HyperCard Infectors 
  7.3  Mac Trojans 
  7.4  Macro viruses, trojans, variants 
  7.5  Other Operating Systems, emulation on a Mac 
  7.6  AutoStart 9805 Worms 
  7.7  Esperanto 4733 

7.1  Mac-specific system and file infectors 
  AIDS - infects application and system files. No intentional damage. 
  (nVIR B strain) 

  Aladin - close relative of Frankie 

  Anti (Anti-A/Anti-Ange, Anti-B, Anti Variant) - can't spread under 
  system 7.x, or System 6 under MultiFinder. Can damage applications 
  so that they can't be 100% repaired. 

  CDEF - infects desktop files. No intentional damage, and doesn't 
  spread under system 7.x. 

  CLAP: nVIR variant that spoofs Disinfectant to avoid detection 
  (Disinfectant 3.6 recognizes it). 

  Code 1: file infector. Renames the hard drive to "Trent Saburo". 
  Accidental system crashes possible. 

  Code 252: infects application and system files. Triggers when run 
  between June 6th and December 31st. Runs a gotcha message ("You 
  have a virus. Ha Ha Ha Ha Ha Ha Ha Now erasing all disks... 
  [etc.]"), then self-deletes. Despite the message, no intentional 
  damage is done, though shutting down the Mac instead of clicking to 
  continue could cause damage. Can crash System 7 or damage files, 
  but doesn't spread beyond the System file. Doesn't spread under 
  System 6 with MultiFinder beyond System and MultiFinder. Can cause 
  various forms of accidental damage. 

  Code 9811: hides applications, replacing them with garbage files 
  named "something like 'FIDVCXWGJKJWLOI'." According to Ken Dunham 
  who reported this virus in November, "The most obvious symptom of 
  the virus is a desktop that looks like electronic worms and a 
  message that reads 'You have been hacked by the Pretorians.'" 

  Code 32767: once a month tries to delete documents. This virus is 
  not known to be in circulation. 

  Flag: unrelated to WDEF A and B, but was given the name WDEF-C in 
  some anti-virus software. Not intentionally damaging but when 
  spreading it overwrites any existing 'WDEF' resource of ID '0', an 
  action which might damage some files. This virus is not known to be 
  in circulation. 

  Frankie: only affects the Aladdin emulator on the Atari or Amiga. 
  Doesn't infect or trigger on real Macs or the Spectre emulator. 
  Infects application files and the Finder. Draws a bomb icon and 
  displays 'Frankie says: No more piracy!" 

  Fuck: infects application and System files. No intentional damage. 
  (nVIR B strain) 

  Init 17: infects System file and applications. Displays message 
  "From the depths of Cyberspace" the first time it triggers. 
  Accidental damage, especially on 68K machines. 

  Init 29 (Init 29 A, B): Spreads rapidly. Infects system files, 
  applications, and document files (document files can't infect other 
  files, though). May display a message if a locked floppy is 
  accessed on an infected system 'The disk "xxxxx" needs minor 
  repairs. Do you want to repair it?'. No intentional damage, but can 
  cause several problems - Multiple infections, memory errors, system 
  crashes, printing problems, MultiFinder problems, startup document 

  Init 1984: Infects system extensions (INITs). Works under Systems 6 
  and 7. Triggers on Friday 13th. Damages files by renaming them, 
  changing file TYPE and file CREATOR, creation and modification 
  dates, and sometimes by deleting them. 

  Init-9403 (SysX): Infects applications and Finder under systems 6 
  and 7. Attempts to overwrite whole startup volume and disk 
  information on all connected hard drives. Only found on Macs 
  running the Italian version of MacOS. 

  Init-M: Replicates under System 7 only. Infects INITs and 
  application files. Triggers on Friday 13th. Similar damage 
  mechanisms to INIT-1984. May rename a file or folder to "Virus 
  MindCrime". Rarely, may delete files. 

  MacMag (Aldus, Brandow, Drew, Peace): first distributed as a 
  HyperCard stack Trojan, but only infected System files. Triggered 
  (displayed a peace message and self-deleted on March 2nd 1988, so 
  very rarely found. 

  MBDF (A,B): originated from the Tetracycle, Tetricycle or 
  "tetris-rotating" Trojan. The A strain was also distributed in 
  Obnoxious Tetris and Ten Tile Puzzle. Infect applications and 
  system files including System and Finder. Can cause accidental 
  damage to the System file and menu problems. A minor variant of 
  MBDF B appeared in summer 1997: Disinfectant and Virex have been 
  updated accordingly. 

  MDEF (MDEF A/Garfield, MDEF B/Top Cat, C, D): infect System file 
  and application files (D doesn't infect System). No intentional 
  damage, but can cause crashes and damaged files. 

  MDEF-E and MDEF-F: described as simple and benign. They infect 
  applications and system files with an 'MDEF' resource ID '0', not 
  otherwise causing file damage. These viruses are not known to be in 

  nCAM: nVIR variant 

  nVIR (nVIR A, B, C - AIDS, Fuck, Hpat, Jude, MEV#, nFlu): infect 
  System and any opened applications. Extant versions don't cause 
  intentional damage. Payload is either beeping or (nVIR A) saying 
  "Don't panic" if MacInTalk is installed. 

  nVIR-f: nVIR variant. 

  prod: nVIR variant 

  Scores (Eric, Vult, NASA, San Jose Flu): aimed to attack two 
  applications that were never generally released. Can cause 
  accidental damage, though - system crashes, problems printing or 
  with MacDraw and Excel. Infects applications, Finder, DA Handler. 

  SevenDust-A through G (MDEF 9806-A through D, also known as 666, E 
  was at first called "Graphics Accelerator"): a family of five 
  viruses which spread both through 'MDEF' resources and a System 
  extension created by that resource. The first four variants are not 
  known to be in circulation. Two of these viruses cause no other 
  damage. On the sixth day of the month, MDEF 9806-B may erase all 
  non-application files on the current volume. The SARC encyclopedia 
  calls MDEF 9806-C, "polymorphic and encrypted, no payload," and 
  MDEF 9806-D, "encrypting, polymorphic, symbiotic," and says the 
  symbiotic part, "alters a 'WIND' resource from the host 
  application." SevenDust E, not to be confused with the legitimate 
  ATI driver "Graphics Accelerator", began as a trojan horse released 
  to Info-Mac and deleted there on or about September 26, 1998. Takes 
  two forms, 'INIT' resource ID '33' in an extension named 
  "\001Graphics Accelerator" and an 'MDEF' resource ID '1' to '255'. 
  Between 6:00 a.m. and 7:00 a.m. on the sixth and twelfth day of any 
  month, the virus will try to delete all non-application files on 
  the startup disk. John Dalgliesh describes "Graphics Accelerator" 
  on his Web page for AntiGax, a free anti-SevenDust E utility; any 
  errors here in translation are not his. SevenDust F uses a trojan 
  "ExtensionConflict", common extensions names, and creator 'ACCE'.[SL] 

  T4 (A, B, C, D): infects applications, Finder, and tries to modify 
  System so that startup code is altered. Under System 6 and 7.0, 
  INITs and system extensions don't load. Under 7.0.1, the Mac may be 
  unbootable. Damage to infected files and altered System is not 
  repairable by Disinfectant. The virus masquerades as Disinfectant, 
  so as to spoof behaviour blockers such as Gatekeeper. Originally 
  included in versions 2.0/2.1 of the public domain game GoMoku. 

  T4-D spreads from application to application on launch by appending 
  itself to the 'CODE' resource. Deletes files other than the System 
  file from the System Folder, and documents, and is termed dangerous. 
  The D strain is not known to be in circulation [SL]. 

  WDEF (A,B): infects desktop file only. Doesn't spread under System 
  7. No intentional damage, but causes beeping, crashes, font 
  corruption and other problems. 

  zero: nVIR variant. 

  Zuc (A, B, C): infects applications. The cursor moves diagonally 
  and uncontrollably across the screen when the mouse button is held 
  down when an infected application is run. No other intentional 
  damage is done. 

7.2  HyperCard infectors 
  These are a somewhat esoteric breed, but a couple have been seen 
  since Disinfectant was last upgraded in 1995, and most of the 
  commercial scanners detect them. 

  Dukakis - infects the Home stack, then other stacks used 
  subsequently. Displays the message "Dukakis for President", then 
  deletes itself, so not often seen. 

  HC 9507 - infects the Home stack, then other running stacks and 
  randomly chosen stacks on the startup disk. On triggering, displays 
  visual effects or hangs the system. Overwrites stack resources, so 
  a repaired stack may not run properly. 

  HC 9603 - infects the Home stack, then other running stacks. No 
  intended effects, but may damage the Home stack. 

  HC "Two Tunes" (referred to by some sources as "Three Tunes") - 
  infects stack scripts. Visual/Audio effects: 'Hey, what are you 
  doing?' message; plays the tune "Muss I denn"; plays the tune 
  "Behind the Blue Mountains"; displays HyperCard toolbox and pattern 
  menus; displays 'Don't panic!' fifteen minutes after activation. 
  Even sources which describe this virus as "Three Tunes" seem to 
  describe the symptoms consistently with the description here, but 
  we will, for completeness, attempt to resolve any possible 
  confusion when time allows. This virus has no known with the PC 
  file infector sometimes known as Three Tunes. 

  MerryXmas - appends to stack script. On execution, attempts to 
  infect the Home stack, which then infects other stacks on access. 
  There are several strains, most of which cause system crashes and 
  other anomalies. At least one strain replaces the Home stack script 
  and deletes stacks run subsequently. Variants include Merry2Xmas, 
  Lopez, and the rather destructive Crudshot. [Ken Dunham discovered 
  the merryXmas virus. His program merryxmasWatcher 2.0 was very 
  popular and still can eradicate the most common two strains, 
  merryXmas and merry2Xmas. merryxmasWatcher 2.0 is outdated for the 
  rest this family.] 

  Antibody is a recent virus-hunting virus which propagates between 
  stacks checking for and removing MerryXmas, and inserting an 
  inoculation script. 

  Independance (sic) Day - reported in July, 1997. It attempts to 
  to be destructive, but fortunately is not well enough written to be 
  more than a nuisance. More information at: 

  Blink - reported in August, 1998. Nondestructive but spreads; 
  infected stacks blink once per second starting in January, 1999. 

7.3  Mac Trojan Horses 
  These are often unsubtle and immediate in their effects: while 
  these effects may be devastating, Trojans are usually very 
  traceable to their point of entry. The few Mac-specific Trojans are 
  rarely seen, but of course the commercial scanners generally detect 

  ChinaTalk - system extension - supposed to be sound driver, but 
  actually deletes folders. 

  CPro - supposed to be an update to Compact Pro, but attempts to 
  format currently mounted disks. 

+ ExtensionConflict - supposed to identify Extensions conflicts, but 
  installs one of the six SevenDust a.k.a. 666 viruses. 

  FontFinder - supposed to lists fonts used in a document, but 
  actually deletes folders. 

  MacMag - HyperCard stack (New Apple Products) that was the origin 
  of the MacMag virus. When run, infected the System file, which then 
  infected System files on floppies. Set to trigger and self-destruct 
  on March 2nd, 1988, so rarely found. 

  Mosaic - supposed to display graphics, but actually mangles 
  directory structures. 

  NVP - modifies the System file so that no vowels can be typed. 
  Originally found masquerading as 'New Look', which redesigns the 

  Steroid - Control Panel - claims to improve QuickDraw speed, but 
  actually mangles the directory structure. 

  Tetracycle - implicated in the original spread of MBDF 

  Virus Info - purported to contain virus information but actually 
  trashed disks. Not to be confused with Virus Reference. 

  Virus Reference 2.1.6 mentions an 'Unnamed PostScript hack' which 
  disables PostScript printers and requires replacement of a chip on 
  the printer logic board to repair. A Mac virus guru says: 

  "The PostScript 'Trojan' was basically a PostScript job that 
  toggled the printer password to some random string a number of 
  times.  Some Apple laser printers have a firmware counter that 
  allows the password to only be changed a set number of times 
  (because of PRAM behavior or licensing -- I don't remember which), 
  so eventually the password would get "stuck" at some random string 
  that the user would not know.  I have not heard any reports of 
  anyone suffering from this in many years." 

  AppleScript Trojans - A demonstration destructive compiled 
  AppleScript was posted to the newsgroups alt.comp.virus, 
  comp.sys.mac.misc, comp.sys.mac.system, it.comp.macintosh, 
  microsoft.public.word.mac, nl.comp.sys.mac, no.mac, and on 16-Aug-97, apparently in 
  response to a call for help originally posted to alt.comp.virus on 
  14-Aug-97 and followup on 15-Aug-97. On 03-Sep-97, MacInTouch 
  published Xavier Bury's finding of a second AppleScript trojan 
  horse, which, like the call for help followup, mentioned Hotline 
  servers. It reportedly sends out private information while running 
  in the background. A note to users from Hotline Communications CEO 
  Adam Hinkley is posted at 
  AppleScripts should be downloaded only from known trusted sources. 
  It is nigh impossible for an average person to know what any given 
  compiled script will do. 

7.4  Macro viruses, trojans, variants 
  At the time of the longstanding second-to-last upgrade of 
  Disinfectant (version 3.6 in early 1995), there were no known macro 
  viruses in the wild, apart from HyperCard infectors. In any case, 
  Disinfectant was always intended to deal with system viruses, not 
  trojans or macro/script viruses. However, many users are unaware of 
  these distinctions and still assume that Disinfectant is a complete 
  solution, even after its effective demise (in fact, there were 
  people still relying on Gatekeeper long after its author disowned 

  Unfortunately, the number of known macro viruses runs into several 
  thousand, though the number in the wild is far fewer. 

  Most macro viruses (if they have a warhead at all) target Intel 
  platforms and assume FAT-based directory structures, so they 
  usually have no discernible effect on Macs when they trigger. 
  Viruses that manipulate text strings within a document may work 
  just as well on a Macintosh as on a PC. 

  In any case, the main costs of virus control are not recovery from 
  virus payloads, but the costs of establishing detection and 
  protection (or of not establishing them). The costs of not 
  establishing these measures can be considerable, irrespective of 
  damage caused on infected machines, especially in corporate 
  environments. Secondary distribution of infected documents may 
  result in: 

  * civil action - for instance, inadvertent distribution of an 
    infected document to external organisations may be in breach of 
    contractual obligations 

  * legal action in terms of breach of data-protection legislation 
    such as the UK Data Protection Act or the European Data Protection 
    directive. The eighth principle of the Data Protection Act, for 
    instance, requires that security measures are taken to protect 
    against unauthorised access to, and alteration, disclosure and 
    destruction of personal data, or its accidental loss. 

  * damage to reputation - no legitimate organisation wants to be 
    seen as being riddled with viruses. 

  Since Word 6.x for Macintosh supports WordBasic macros, it is as 
  vulnerable as Word 6.x and 7.x on Intel platforms to being infected 
  by macro viruses, and therefore to generating other infected 
  documents (or, strictly speaking, templates). Working Excel viruses 
  are now beginning to appear also, and any future Macintosh 
  application that supports Visual Basic for Applications will also 
  be vulnerable. Note also that the possibility of virus-infected 
  files embedded as objects in files associated with other 
  applications: this possibility exists on any platform that supports 

++Office 98 is in general vulnerable to infection by most viruses which 
  affect corresponding applications in Office 97. 

  Macro viruses are therefore highly transmissible via 
  Macintoshes, even if they don't have a destructive effect on 
  Motorola platforms, if there is an equivalent application 
  available on the Macintosh. For instance, although Word for 
  Windows versions before vs. 6 support WordBasic, Word 
  versions for the Mac up to and including version 5.1 do not. 
  [Thus Word 5.1 users can not be directly infected, but may, 
  like anyone, pass on infected documents to vulnerable systems.]] 

  Network Associates, Symantec, and Intego all make known-virus 
  scanners that detect a range of macro viruses. Microsoft make 
  available a free 'protection tool' whose effectiveness is often 
  overestimated. (See below.) 

++[I'm no longer able to find any reference on Intego's site to Rival: 
their efforts seems to be focused on their personal firewall for Macintosh.] 

  For further information on specific macro viruses, try one of the 
  information resources given earlier. 

7.5  Other Operating Systems, emulation on a Mac 
  Any Mac running any sort of DOS or Windows emulation such as 
  Virtual PC, SoftPC, SoftWindows, RealPC, or a DOS compatibility 
  card is a potential target for any PC virus, including Boot Sector 
  Infectors/Multipartites; (effects will vary). It is highly 
  recommended that anyone with such a system should run a reputable, 
  up-to-date PC antivirus program under emulation, as well as a good 
  Mac antivirus program. [Dr. Solomon's for the Mac detected PC boot 
  sector infectors as well as Mac viruses, but didn't detect PC file 
  viruses (apart from macro viruses), and so was not sufficient 
  protection for a Mac with DOS emulation.] 

  Recommendations for defending PC systems or PC emulation on Macs 
  are slightly out-of-scope for this FAQ. In fact, I don't know of 
  any formal testing for PC antivirus software in the context of PC 
  emulation on Macs. I've done some informal testing (referred to in 
  another paper), but am not prepared to make vendor-specific 
  recommendations on the basis of such testing. F-Prot, AVP, and Dr 
  Solomon's are particularly well-regarded PC antivirus packages, of 
  which some components on some platforms are available as freeware 
  or for evaluation, but their efficacy in the context of PC 
  emulation is not well tested or documented. 

  To find a commercial or shareware package relevant to PCs, check 
  through the independent comparative reviews sites: 
  University of Hamburg Virus Test Center 
  University of Tampere Virus Research Unit 
  Secure Computing 
  Virus Bulletin 

+ has an aggregation of PC anti-virus reviews links. 

  Robert Michael Slade's lists may also be helpful. 

7.6  AutoStart 9805 Worms 
  AutoStart 9805 is not a virus, but a worm: that is, it replicates 
  by copying itself, but doesn't attach itself parasitically to a 
  host program. The original took hold rapidly in Hong Kong and 
  Taiwan in April 1998, and has been reported on at least four 
  continents. In addition to the original worm, there are five 
  variants. Virus Bulletin, July, 1998, includes a comprehensive 
  analysis of AutoStart and some of its variants. 

  CIAC Bulletin I-067 is based on Eugene Spafford's information 
  release on the original AutoStart worm. Unfortunately,this is now a 
  little out-of-date, particularly as regards the update status of 
  the antivirus software it mentions. Nor does it mention any of the 
  subsequently discovered variants. 

  Symptoms: Perhaps the most noticeable symptom of the worms is that 
  an infected system will _lock up and churn with unexplained disk 
  activity_ every 6, 10, or 30 minutes.[SL] 

  Affected platforms: any PowerMac. Macintoshes and clones driven by 
  Motorola 680x0 series CPUs can't run the replicative code. It works 
  under any version of Mac OS, if QuickTime 2.0 or later is installed 
  and CD-ROM AutoPlay is enabled in the "QuickTime Settings" Control 

  Transmission media: HFS or HFS+ volumes (hard disks, diskettes, 
  most types of removable media, even disk images). Audio CDs can't 
  transmit the virus, and it isn't necessary to disable "Audio CD 

  Transmission method: infected media contain an invisible 
  application file named "DB" or "BD" or "DELDB" in the root 
  directory (type APPL, creator ????). This is an AutoStart file: 
  i.e. it will run automatically if CD-ROM autoplay is enabled. If 
  the host Mac isn't already infected, it copies itself to the 
  Extensions folder. The new copy is renamed "Desktop Print Spooler" 
  or "Desktop Printr Spooler", or "DELDesktop Print Spooler" 
  respectively (type appe, creator ????). Unlike the legitimate 
  Desktop Printer Spooler extension, the worm file has the invisible 
  attribute set, and isn't listed as a running process by the system 
  software, though it can be seen with Process Watcher or Macsbug. 
  After copying itself, it reboots the system and is now launched 
  every time the system restarts. At approximately 6, 10, or 30 
  minute intervals, it examines mounted volumes to see if they're 
  infected: if not, it writes itself to the root directory and sets 
  up AutoStart (however, AutoStart won't work on a server volume). 

  Damage: files with names ending "data", "cod" or "csa" are targeted 
  if the data fork is larger than 100 bytes. Files with names ending 
  "dat" are targeted if the whole file is c. 2Mb or larger. Targeted 
  files are attacked by overwriting the data fork (up to the 1st Mb) 
  with garbage. 

  Besides the original, there are five variants: AutoStart 9805-B, 
  which is less noticeable but can cause irreparable damage to files 
  of type 'JPEG', 'TIFF', and 'EPSF'; AutoStart 9805-C and AutoStart 
  9805-D which do not intentionally damage data; AutoStart 9805-E 
  which spreads like B and is most similar to the original; and 
  AutoStart 9805-F which is most similar to A and E. 
  Dr Solomon's, Sophos, and Symantec had descriptions on the Web: 
++Dead Mac Virus link cleaned. 

  Detection: updates to deal with the worms are available for Virex 
  (, for NAV and SAM 
  (, and for Rival 

  The last versions of VirusScan for Mac and Disinfectant did not detect 
  AutoStart. [Reference to Dr Solomon's for Mac removed, as the product is 
  no longer supported.] 

  Prevention: uninfected systems can be protected by disabling the 
  AutoStart option in QuickTime settings (QuickTime 2.5 or later only 
  - earlier versions don't have a disable option). This should also 
  prevent infection by future malware exploiting the same loophole, 
  but will fail if a setup is booted from a volume with an infected 
  Extensions Folder [SL]. 

  Removal: the easiest and safest method for most people will be to 
  use the updated version of their favoured anti-virus software, as 
  it becomes available. 

  The worms can be also be removed manually. 
  * Reboot with extensions disabled (hold down the shift key till an 
    alert box tells you that extensions are off). 
  * Use Find File to search all volumes for all instances of a file 
    called "DB" or "BD" or "DELDB" with the invisibility attribute set 
    (hold down Option key when clicking on "Name" pop-up menu to select 
    for visibility). Trash 'em. 
  * Use Find File to find and trash an invisible "Desktop Print 
    Spooler", "Desktop Printr Spooler", or "DELDesktop Print Spooler" 
    file (-not- Desktop Printer Spooler, which is a legitimate and 
    usually necessary system file). 
  * Empty the trash. 
  * Disable AutoStart in QuickTime Settings Control Panel. 
  * Restart. 

7.7  Esperanto.4733 
  This probably doesn't belong here. It's a PC file infector which 
  works with a number of PC executable file formats. When it was 
  first seen, it was reported to be a multiplatform virus capable of 
  executing under some circumstances on Macintoshes. Subsequent 
  reports indicate that this belief results from misinformation on 
  the part of the author. However, at least two reputable PC 
  anti-virus vendors still list it as capable of activating on a 
  Macintosh. No Mac scanner is known to attempt to detect it.

8.0  What's the best antivirus package for the Macintosh? 

  As ever, we can't give a definitive answer to this. The best choice 
  depends on subjective criteria and individal needs. Nonetheless, 
  Here are some thoughts on the main contenders. 

8.1  Microsoft's Protection Tools 
  Microsoft's Macro Virus Protection Tools originally detected 
  Concept (Nuclear and DMV were also mentioned in the documentation, 
  but were not identified specifically by the tools). Principally, 
  they merely warned users that the document they are about to open 
  contained macros and offered the choice of opening the file without 
  macros, opening it with macros, or cancelling the File Open. Later 
  implementations built into the application are better on 
  identifying a few specific viruses and on integration into Word 
  itself, but should not be relied on for 100% effective detection, 
  blocking and disinfection of macro viruses. More information from 
  Microsoft may be available at the addresses below. 
  <> (no longer accessible) 
  AOL: the Word forum 
  CompuServe: the Word forum 
  Microsoft Product Support Services 
  206-462-9673 (WinWord) 
  206-635-7200 (Word Mac) 

  NB The Protection Tool traps some File Open operations, but not 
  all. There are a number of ways of opening a document which bypass 
  it, some of which are rather commonly used (e.g. double-clicking or 
  using the Recent Documents list). 

  The Protection Tool can be used to scan for Concept-infected files, 
  but there are a number of possible problems with it. 

  * Earlier versions could only handle a limited size of directory 
    tree, and ran very slowly if a large number of files required 
    scanning. Speed is certainly still a problem: I can't say about the 
    overflow problem. 
  * Files created in Word for Windows won't be scanned until they've 
    been opened in Word 6 for Mac (this is a system issue, not a bug in 
    the code). However, Microsoft suggest that you open the file in 
    Word for the Macintosh and save it before scanning. This will do 
    the job, but will also infect your system, if the file is infected. 
    If it's infected with a virus -other- than Concept, this could 
    create problems if the Protection Tool is bypassed on a subsequent 
    file open. 
  * Infected files embedded in OLE2 files or e-mail files will not be 
  * The Microsoft tools are not useful on non-English Windows systems 
    (which may be run under Virtual PC or Real PC). SCANPROT cannot 
    handle non-English documents, and will hang during the scanning 
    process if it encounters a document created with a non-English 
    version of Word. Microsoft's Excel add-in for the Laroux macro 
    virus causes multiple file open buttons to appear in non-English 
    versions of Excel, and so it has worse effects than the macro virus 
    itself. Again this applies to Windows emulation; however, most 
    virus protection and detection products are only tested in an 
    English language environment, and may cause problems on non-English 
    systems. [Thanks to Eric Hildum for this information.] 

  Windows 95 users should be aware that SCANPROT is not recommended 
  for use with MS Word 7.0a for Windows with internal detection 
  enabled, as these two tools will cancel each other out. 

  The Excel add-in for Macs removes only Laroux A and B. 

++Office 98 moves the goalposts again. This issue will probably be 
  addressed again here in more depth. In brief, Office 98 does a 
  better job of implementing a primarily generic approach [i.e. "If 
  it contains macros, it's suspicious: sort it out yourself...."], 
  but whether this is enough is a question demanding more space and 
  time than I have to spare right now. Office 97/98 include limited 
  detection of a handful of known viruses during upconversion of 
  macros. This is poorly implemented and in any case is only triggered 
  when macros are converted to VBA from WordBasic. Vesselin Bontchev 
  has considered macro upconversion at some length in papers for 
  Virus Bulletin and EICAR conferences. 

++Microsoft's home page has recommended using an ICSA-certified 
  antivirus utility and sidesteps any hint of responsibility for any 
  macro virus or SCANPROT related problems. However, ICSA does not 
  currently certify Mac products, though this is being looked at. 

8.2  Disinfectant 
  [On May 6th 1998, John Norstad, author of this widely-used freeware 
  package announced that it was to be retired. 3.7.1 is the latest 
  and last version, and it won't be updated to detect AutoStart 9805 
  or any subsequent Macintosh malware. The main reason for this is 
  that he doesn't have the resources to extend its capabilities to 
  detect macro viruses, which have become by far the most significant 
  virus problem for most Macintosh users. 

  This is probably a wise decision, given the number of people who 
  still overestimate the effectiveness of the package in the face of 
  the macro virus threat. However, the entire Macintosh community 
  owes John Norstad a debt of gratitude for making it freely 
  available for so long, an act of altruism which has probably 
  contributed very significantly to the comparative rarity of native 
  Macintosh viruses.] 

  Disinfectant was an excellent anti-virus package with exemplary 
  documentation, and didn't cost a penny: however, it didn't detect 
  all the forms of malware that a commercial package usually does, 
  including HyperCard infectors, most Trojans, jokes or macro 
  viruses. Unlike some commercial packages, it didn't scan compressed 
  files, either: compressed files had to be expanded before scanning. 
  Self-extracting archives were probably best scanned before 
  unpacking, then again when unpacked. 

  Disinfectant has been available up to now from the following 
  sources, but this may not continue to be the case.: 
  America Online 
  Info-Mac mirrors in the ../vir/ directory 

  The Disinfectant README was updated to README-IMPORTANT on 6 May 
  1998, with the message, "because of the widespread and dangerous 
  Microsoft macro virus problem," "...All Disinfectant users should 
  switch..." to another program. README-IMPORTANT was updated again 
  on 11 October 1998, adding, "In addition to the Autostart worm and 
  the Microsoft macro viruses, several other new Mac viruses have 
  appeared since Disinfectant's retirement in May. This makes it even 
  more important that Disinfectant users switch..." to one of the 
  commercial products. 
  There is a copy of the retirement announcement on the Web: 

8.3  Demo Software 
  Symantec has a 30-day fully-functioning trialware NAV (Norton 
  AntiVirus for Macintosh). Update it with current definitions. 

  Network Associates has a 30-day fully-functioning evaluation 
  version of Virex 5.9.1. The Virex trial includes the application, 
  not the control panel. 
  Update the demo with current definitions: 

  Sophos also has a 30-day evaluation, also fully-functioning, 
  which includes the SWEEP application. The demo supports both 
  English and Japanese. 

++Intego has a limited-function French demo of Rival, "miniRival." 
  <> [This seems to have disappeared, 
  along with Rival itself - 11-12-99] 

  Disinfector 1.0 is described by its author as shareware. However, 
  it's strictly speaking a limited-runtime demo -- it stops 
  functioning after 20 trial runs on one system. It's described as a 
  beta release, but the author expects users to register it at a 
  charge of $30 [subsequently reduced to $15]: in return, they get a 
  version which can be used an unlimited number of times. It only 
  detects a handful of Mac system viruses which the author claims 
  that commercial vendors have not detected, and have not been 
  reported in the wild. In the early days of virus/antivirus 
  technology, a number of utilities were made available which 
  addressed only one or a few viruses, and a proliferation of free 
  AutoStart worm detectors continues that honourable tradition. 
  However, charging for this particular utility puts it into the same 
  arena as the commercial scanners which detect a far wider range of 
  threats and for which full support is available, an area in which 
  it cannot at present compete. Disinfector was briefly available at 
  Info-Mac, but has since been removed. 
++[I suspect that this product has been removed from circulation, but 
haven't checked with the author. This section will probably be amended 
or removed in the next version of the FAQ, when I've checked.] 

  There have also been a number of proposals since John Norstad 
  announced the retirement of Disinfectant, suggesting that if the 
  code was made public, it would be possible to maintain and further 
  develop Disinfectant, possibly still as a freeware product. This is 
  misguided, for a number of reasons. 

  * It misses one of the main points of Norstad's announcement, which 
    is to acknowledge the dangers of continuing to develop a scanner 
    which detects only one class of virus, when so many people have 
    laboured so long under the misapprehension that it was a complete 
  * Disinfectant -has- been developed further. VirusScan is based on 
    Disinfectant technology (under licence), and NAI are in a much 
    better position to develop it as commercial-grade software than a 
    group of well-meaning individuals without the specialised skills 
    and resources of a mainstream anti-virus development team. Indeed, 
    it may be that the terms of that agreement would prevent Norstad 
    from making the code public even if he wanted to (I doubt that he 
  * Making the code public, even to a limited circle, would increase 
    the chances of its falling into irresponsible hands. In fact, the 
    online documentation has long stated that the code for the 
    detection engine is not available, though some of the interface 
    code was. (I'm paraphrasing from memory: I may well check out 
    exactly what it says for the next update of the FAQ.) 
  * To think that a committee of well-intentioned amateurs (or a 
    single ambitious amateur can develop Disinfectant to the same high 
    standard that it achieved through its lifetime demonstrates a 
    profound underestimation of the difficulties of maintaining (let 
    alone creating) a first-class known-virus scanner. [DH] Curiously, 
    the same fallacies have recently been been aired on a Unix virus 
    discussion list. 

8.4  Other freeware/shareware packages 
  For other freeware\shareware Mac packages, try Info-Mac mirrors 

  The University of Texas holds some older documentation on Mac 

  Tracker INIT and DelProtect INIT, both by Ioannis Galidakis, were 
  first released on 19-Nov-98. Tracker is a behavior blocker something 
  like the retired program GateKeeper. DelProtect protects against 
  malicious file deletion. Tracker is now at version 1.1. Scanner 1.1x 
  also by Ioannis Galidakis was released 15-Jan-99, and is a free, 
  generic, heuristic 68k virus scanner for advanced Macintosh users. 

  John Dalgliesh has created Agax, an extensible, free anti-virus 
  program which replaces his program AntiGax, and uses plug-ins called 
  "Additives." At this time, Agax will detect and try to clean only 
  SevenDust, CODE 9811, and the AutoStart worms (the worm additive was 
  in beta testing at the time of this writing). The author's Web page 
  and documentation invite Mac programmers to contribute additives. 

  The Exorcist, free from Laffey Computer Imaging, may give some (by 
  one description, about 90%) protection from the SevenDust family. 

  Gatekeeper was not a scanner, but a generic tool. It is no longer 
  supported by its author, but is still available on some sites. It 
  is probably not safe to use or rely on on modern systems, and I 
  believe the author recommends that people don't attempt to use it, 
  though I've been unable to contact him to get confirmation. 

  In January 1997 Padgett Peterson, author of the PC utility 
  DiskSecure, released the first version of his MacroList macro 
  detection tool, which has been tested by the author on Macs (System 
  7.5 on SE/30, IIci and PowerMac) as well as Windows PCs, using 
  considerably more macro viruses than Microsoft seem to have heard 
  of..... The MacroList template is accessed by a button in the 
  standard toolbar. This is not a virus scanner, but allows disabling 
  of automacros, listing of any macros found in the current document 
  etc. Version 1.10 was due for release by the time of writing 
  (February 1997), and an adaptation for Office97 is in progress. 
  Watch the Web page for further details. [v1.1 and the Office 97 
  "late beta" were available as at 18th March 1997.] MacroList is 
  freeware, but please be sure to read the TRIALS link. 
  (under Anti-Virus Hobby) - NB change of URL. 

  WormGuard by Clarence Locke is a free on-access extension that 
  affords AutoStart worm protection: 

  The following free scanners may remove AutoStart 9805 and its B, C, 
  D, E, and F variants and may be useful in the absence of a 
  commercial application. There are a few reported instances of 
  failures by some of these programs to identify or remove the 
  AutoStart worms, and it is likely that D might be mis-identified as 
  C, and E may be mis-identified as the original worm. [SL] 

  WormScanner by James Walker 
  Autostart Hunter by Akira Nagata 
  <> (English) 
  <> (Japanese) 
  BugScan by Mountain Ridge Dataworks (also detects SevenDust E) 
  Worm Gobbler by Jim Kreinbrink 
  Innoculator by MacOffice 
  WormFood by Doug Baer 
  Eradicator with update, by Uptown Solutions Ltd. 

  As stated above, one-shot solutions to a very small subset of a 
  particular class of threat have a long and honourable history, and 
  are very welcome when a new threat catches the antivirus developers 
  on the hop (it can take some time to incorporate detection of new 
  threats into the product update cycle). NB The maintainer does not 
  currently have the time or resources to do full detection testing of 
  these products (or any other). [DH] 

8.5  Commercial Packages 
  Commercial packages include NAV (Norton AntiVirus for Macintosh) 
  [NAV supersedes SAM (Symantec Antivirus for Macintosh)], Virex for 
  Macintosh, Rival, and Sophos Anti-Virus for Macintosh (SAV). 

  Virex, NAV, and SAM [obsolete] all address a full range of threats, 
  including Trojans and macro viruses, and can do scheduled scanning 
  as well as on-access (memory-resident) scanning. 

++Sophos Anti-Virus for Macintosh (SAV) was upgraded in January 1999 
  to include the SWEEP on-demand scanner. The shipping version can be 
  downloaded for free evaluation. English and Japanese are supported. 
  <> Stand-alone on-access scanning 
  is now available in the release version. Server-based on-access scanning 
  has long been available for Mac clients on NT or NetWare networks. 
  The program offers customizable reporting and notification from an 
  attractive interface. So far, compressed archives must be 
  decompressed before scanning; I am assured that archive scanning 
  will be in future versions. Complete documentation is in PDF format. 
+ Sophos combines an intercept driver (InterCheck) and a scanner 
  application (SWEEP). Sales are not retail, but direct or through 
  the Sophos Distributor network. Free technical support is all-year 
  round, any time of day. Virus identity updates are available from 
  the Web between monthly CD-ROMs. Major developments in the Sophos 
  product are expected, including smooth large-scale deployment and 
  ease of updating over networks.[SL] 
[This section is overdue for serious refurbishment. Next FAQ release, maybe. There 
may be an issue with the Sophos control panel and some USB drives - not formally 
tested to date.] 

  Norton AntiVirus for Macintosh (NAV) launched May 18, 1998. New 
  features included LiveUpdate virus definition updates over the 
  Internet, enhanced macro virus protection, automatic file repair, a 
  bootable CD-ROM for emergencies, faster scanning for PPC, and a 
  universal SafeZone. 

  NAV, SAM, and Virex offer checksumming/integrity checking 
  (detecting possible infection by unknown viruses, by monitoring 
  changes in infectable files) - the correct checksums or 
  fingerprints for individual files are kept in a database file. All 
  three applications check files compressed with StuffIt. 

  NAV, formerly SAM, is particularly oriented towards behaviour 
  blocking: the Intercept tool can be configured to raise an alert at 
  the slightest whiff of a 'suspicious' operation. Unfortunately, 
  this can be counterproductive in real life, since an over-stringent 
  alert policy is apt to result in the facility being turned off 
  altogether. However, configuration is very flexible. 

  SAM (Symantec AntiVirus for Macintosh) support was discontinued 
  May 1; the last update is for July '99. From Symantec's advice: 
   "In order to maintain the safety and security of your data 
    from viruses without interruption, we recommend that you 
    upgrade to NAVM 5.0.3 before May 1st. For presales and 
    upgrade questions, please contact customer service. They 
    can be reached at 800-441-7234 or online at:" 

  [SAM 4.5.x needs the 4.5->4.5.1 application patch to run current 
  definitions, and the 4.5.3 Intercept patch to resolve a compatibility 
  issue with Microsoft Office 98, and Segment Loader errors when 
  Intercept loads. 
  SAM application Minimum and Preferred memory allocations must be 
  increased from their shipping defaults to 5000K or greater. The 
  (May 1998) SAM definitions files included a Read Me with 
  instructions. More information may be available from Symantec SAM 
  support on the Web.] 

  Symantec issued a Norton AntiVirus 5.x->5.0.3 patch for Mac OS 8.5, 
  fixing the problem with copying files on AppleShare networks. 

  Virex offers very fast scanning is easy to update, and includes 
  checksumming for the detection of unknown viruses. It's also 
  possible to buy an administration package. The basic package 
  includes a control panel for scanning on file or diskette access 
  which can be locked independently of the administration package. 
  Installation and interface are easy and efficient. Virex 5.8 scans 
  ZIP archives, has a contextual menu plug-in module, and interface 

  Virex 5.9.1 was released on 18-Jan-99, for compatibility with 
  Mac OS 8.5 and Virex Administrator 1.4, and can be downloaded. 
  <>. Registered users who 
  bought McAfee VirusScan during the past six months or so, and 
  registered users of Virex 5.8 and 5.9 could still upgrade: 
  Virex Administrator version 1.4 was released by NAI on 23-Dec-98. 
  Virex and Virex Administrator had these home pages: 
++Current Virex release is 6.0. Licensed 5.9x users can obtain an 
  upgrade. OS 9 users will need the beta control panel available from, to overcome compatibility problems. 

  Dr Solomon's Software acquired Virex and netOctopus from Datawatch 
  Corp. on 10-Oct-97. Network Associates (NAI) acquired Dr Solomon's 
  on 13-Aug-98. Netopia, Inc., acquired what is now named Timbuktu 
  netOctopus in late '98 or early '99. 

++VirusScan 3.0.1 is the final version for Macintosh, and may be 
  updated for macro viruses into 1999, but will never have AutoStart 
  worm definitions or definitions for the new System viruses like 
  SevenDust E. VirusScan customers need to take advantage of a free 
  upgrade to Virex as soon as possible. 

  Dr. Solomon's for Macintosh went through various stages of neglect 
  through late 1998 and support appears to have vanished altogether in 
  1999, when customers started to receive Virex disks instead of Dr. 
  Solly's updates. 

++Rival 3.0.4 is available from Intego. [Probably obsolete info.] 

++F-Secure for Macintosh is one of the best-kept secrets in anti-virus. 
  The last time I saw it, it detected macro viruses only. You might be 
  lucky and find some reference to it at: 
  It features on datafellows evaluation CDs.

8.6  Contact Details 
  Network Associates 
  (for Virex, Dr Solomon's Anti-Virus Toolkit, and VirusScan) 

  Network Associates Corporate Headquarters 
  3965 Freedom Circle 
  McCandless Towers 
  Santa Clara, CA 95054 
  United States 
  Customer Care: 
  Voice +1 408 988 3832 
  Fax   +1 408 970 9727 
  Fax-back automated response system 
  +1 408 988 3034 
  BBS   +1 408 988 4004 
  America Online keyword: MCAFEE 
  CompuServe: GO NAI 

  Dr. Solomon's Software Ltd. 
  (for Dr. Solomon's Anti-Virus Toolkit) 

  Alton House 
  Gatehouse Way 
  Buckinghamshire HP19 3XU 
  United Kingdom 
  UK Support: 
  US Support: 
  UK Tel: +44 (0)1296 318700 
  USA Tel: +1 781-273-7400, 1-888-DRSOLOMON 
  CompuServe: GO DRSOLOMON 

  Symantec Corporation (for NAV and SAM) 

  10201 Torre Avenue 
  Cupertino CA 95014 
  United States 
  +1 408 725 2762 
  Fax: +1 408 253 4992 
  US Support:  541-465-8420 
  European Support:  31-71-353-111 
  Australian Support:  61-2-879-6577 

  Intego (for Rival) 

  10, rue Say 
  75009 Paris 
  +33 1 49 95 07 80 
  Fax: +33 1 49 95 07 83 

  Sophos Plc (for Sophos Anti-Virus) 

  The Pentagon 
  England OX14 3YP 
  US Support: +1-888-SOPHOS-9 
  UK Support: +44-1235-559933 

++Details on DataFellows will be included when I've determined the current 
  status of F-Secure for Macintosh. [Sorry: next time round, guys....] 

9.0  Welcome Datacomp 

  From time to time there are reports from Mac users that the message 
  'Welcome Datacomp' appears in their documents without having been 
  typed. This is the result of using a Trojanised 3rd-party 
  Mac-compatible keyboard with this 'joke' hard-coded into the 
  keyboard ROM. It's not a virus - it cannot infect anything. The 
  only cure is to replace the keyboard (be polite but firm with the 
  dealer if you were sold this as a new keyboard!). 

10.0  Hoaxes and myths 

  Some of these are PC-specific, rather than Mac-specific, while some 
  have no basis in reality on any system. [I look forward to hearing 
  about the first Turing machine infector....] They are included here 
  (a) because Mac support staff are accustomed to being asked about 
  them (b) because anything that -might- work on a real PC -might- 
  also work with DOS emulation, in principle. 
++This section may vanish in the near future, or at least contract. 
  The hoax business has changed a lot since this FAQ began. 

10.1  Good Times virus 
  There is *no* Good Times virus that trashes your hard disk and 
  launches your CPU into an nth-complexity binary loop when you read 
  mail with "Good Times" in the Subject: field. 

  You can get a copy of the latest version of Les Jones' FAQ on the 
  Good Times Hoax on the World Wide Web: 

  There's a Mini-FAQ available as: 

10.2  Modems and Hardware viruses 
  There is no modem virus that spreads via an undocumented subcarrier 
  - whatever that means.... There is no virus that causes damage to 

10.3  Email viruses 
  Any file virus can be transmitted as an E-mail attachment. However, 
  the virus code has to be executed before it actually infects. 
  Sensibly configured mailers and browsers don't allow this: check 
  yours. In particular, check that your Web browser doesn't 
  automatically pass Word documents to Word 6 to open, since this may 
  result in embedded macros being launched. 

10.4  JPEG/GIF viruses 
  There is no known way in which a virus could sensibly be spread by 
  a graphics file such as a JPEG or .GIF file, which does not contain 
  executable code. Macro viruses work because the files to which they 
  are attached are not 'pure' data files. 

10.5  Hoaxes Help 
  If you should receive a virus warning, look at these sites before 
  forwarding it along (in fact, it's probably never justified to pass 
  on a virus alert indiscriminately, and reputable antivirus 
  companies don't do this. In fact, the information that such and 
  such a virus exists is not, in itself, useful to the average 
  computer user, even if it does. A statement like, "Please forward 
  to everyone!" is one mark of a hoax. 

  Computer Virus Myths home page 


  Data Fellows 

  Scams and Hoaxes FAQ: Messages you DON'T want to post 

  Corporates who haven't sorted out their hoax management strategy 
  might get some mileage out of my mini-paper on "Dealing with 
  Internet Hoaxes", though it's getting a bit long in the tooth. It 
  is, however, one of the few papers on the subject which deals with 
  it from an adminstrator's/manager's point of view as well as from 
  an everyday user/victim's. [DH] 
  I'm slightly surprised to find that I'm managing an EICAR project 
  in this area: watch this space. 

11.0  Glossary 

  * Change Detectors/Checksummers/Integrity Checkers - programs that 
    keep a database of the characteristics of all executable files on a 
    system and check for changes which might signify an attack by an 
    unknown virus. 
  * Cryptographic Checksummers use an encryption algorithm to lessen 
    the risk of being fooled by a virus that targets that particular 
  * Dropper - a program that installs a virus or Trojan, often 
  * Generic - catch-all name for antivirus software that doesn't know 
    about individual viruses, but attempts to detect viruses by 
    detecting virus-like code, behaviour, or changes in files 
    containing executable code. 
  * Heuristic scanners - scanners that inspect executable files for 
    code using operations that might denote an unknown virus. 
  * Monitor/Behaviour Blocker - a TSR that monitors programs while 
    they are running for behaviour which might denote a virus. 
  * Scanner (conventional scanner, command-line scanner, on-demand 
    scanner) - a program that looks for known viruses by checking for 
    recognisable patterns ('scan strings', 'search strings', 
    'signatures') or using a more flexible algorithmic approach for 
    detection of polymorphic viruses, which can't be found by a search 
    for a simple scan string. These are not usually associated with the 
    Macintosh platform, but there are Word Macro viruses which exhibit 
  * Trojan (Trojan Horse) - a program intended to perform some covert 
    and usually malicious act that the victim did not expect or want. 
    It differs from a destructive virus in that it doesn't reproduce, 
    (though this distinction is by no means universally accepted). 
  * Virus - a program (a block of executable code) that attaches 
    itself to, overwrites or otherwise replaces another program in 
    order to reproduce itself without the knowledge of the computer 
    user. Most viruses are comparatively harmless, and may be present 
    for years with no noticeable effect: some, however, may cause 
    random damage to data files (sometimes insidiously, over a long 
    period) or attempt to destroy files and disks. Others cause 
    unintended damage. Even benign viruses (apparently non-destructive 
    viruses) cause significant damage by occupying disk space and/or 
    main memory, by using up CPU processing time, by introducing the 
    risk of incompatibilities and conflicts, and by the time and 
    expense wasted in detecting and removing them. 

12.0  General Reference Section 

12.1  Mac Newsgroups 


  The focus on these two groups tends to be IBM-compatible, but Mac 
  issues are certainly aired. Alt.comp.virus is unmoderated, and the 
  quality of the advice and opinions aired there is very variable - 
  there are many reputable and expert posters, and many mischievous 
  and misleading contributions. Caveat lector.... comp.virus lies 
  dormant for years at a time, but is well worth watching when there's 
  anything there. 

12.2  References and Publications 
  Sensei Consulting Macintosh WAIS Archives 

  "Inside the Apple Macintosh" - Peter Norton & Jim Heid (Brady) (The 
  2nd Edition is pre-PowerMac, and I haven't seen a later one, but 
  there's some surprisingly useful stuff in there). 

  "Inside Macintosh" (Addison Wesley). Essential reading for Mac 
  programmers. (Umpteen volumes of fairly low-level info. Expensive 
  (in the UK, at any rate), and whenever you get near some useful 
  info, it refers you to one of the volumes you haven't got. However, 
  the series has been re-vamped since I acquired my copies, and this 
  may be less than just. It's possible to download them in Acrobat 
  and in some cases other formats from: 
  where you can also order hardcopy and CD versions. Lots of other 
  useful files. 

  "Power Macintosh Emergency Handbook" (Apple Computer) 

  MacFixIt "Troubleshooting for the Macintosh" 

  "Sad Macs, Bombs and other Disasters" 
  Ted Landau (Addison Wesley) 

  MacInTouch home page (info and services) 
  <> (Have run MacInTouch columns about the AutoStart worms.) 
  Macworld magazine 
  TidBITS (Have done many good articles on Mac/macro virus issues.) 

13.0  Mac troubleshooting 

  Since the initial release of this document, a number of people have 
  E-mailed me asking for help with a possibly virus-related problem. 
  While I'll always help if I can, I should point out (1) I'm an 
  experienced Mac user and an IT support professional, but I don't 
  claim to be a Mac expert (2) pressure of work and other commitments 
  and a huge E-mail turnover means that I can't promise a quick or 
  in-depth response [DH]. Whether you mail direct or post to a 
  relevant newsgroup, it's helpful if you can supply a few details, 
  such as: 

  * Which model of Macintosh you're using. It may be useful to know 
    how much RAM it has, the size of the hard disk, and any peripherals 
    you're using. 
  * Which version of MacOS you're using. 
  * Which applications you're using, and which version. If you're 
    using Word, it may be critical to know whether you're using version 
    6 or later, or an earlier version. 
  * Which, if any, antivirus packages you use, and what version 
    number. If you're using NAV, for instance, what version? 
  * List any error messages or alerts that have appeared. 
  * List any recent changes in configuration, additional hardware 
  * List any diagnostic/repair packages you've tried, and the 
  * List any other steps you've taken towards determining the cause 
    of the problem and/or trying to fix it, e.g. rebuilding the 
    desktop, booting without extensions, zapping PRAM etc. 

  Here are a few steps that it might be appropriate to try if virus 
  scanning with an up-to-date scanner finds nothing. This section 
  will be improved when and if I have time. 

  Rebuilding the desktop is by no means a cure-all, but rarely does 
  any harm. It may be worth disabling extensions when you do this, 
  especially if the operation doesn't seem to be completed 

  To disable extensions, restart the machine with the shift key held 
  down until you see an Extensions Off message. If you're rebuilding 
  the desktop, release the shift key and hold down Command (the key 
  with the Apple outline icon) & Options (alt) until requested to 
  confirm that you want to rebuild. 

  Disabling extensions is also a good starting point for tracking 
  down an extensions conflict. If booting without extensions appears 
  to bypass the problem, try removing extensions with Extensions 
  Manager (System 7.5) - remove one at a time, and replace it before 
  removing the next one and booting with that one removed. Remember 
  that if removing one stops the problem, it's still worth putting it 
  back and trying all the others to see if you can find one it's 
  conflicting with. Extensions Manager also lets you disable control 
  panels. If you don't have Extensions Manager, try Now Utilities or 
  Conflict Catcher. 

  Parameter RAM (PRAM) contains system information, notably the 
  settings for a number of system control panels. 'Zapping' PRAM 
  returns possibly corrupt PRAM data to default values. A likely 
  symptom of corrupted PRAM is a problem with date and time (but 
  could be a symptom of a corrupted system file). With system 7, hold 
  down Command-Option-P-R at bootup until the Mac beeps and restarts. 
  You may have restore changes to some control panels before your 
  system works properly. If the reset values aren't retained, the 
  battery may need replacing. 

End "Viruses and the Macintosh" version 1.6a by David Harley 

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Last Update March 27 2014 @ 02:11 PM