34.8. Security Issues

A brief warning about script security is appropriate. A shell script may contain a worm, trojan, or even a virus. For that reason, never run as root a script (or permit it to be inserted into the system startup scripts in /etc/rc.d) unless you have obtained said script from a trusted source or you have carefully analyzed it to make certain it does nothing harmful.

Various researchers at Bell Labs and other sites, including M. Douglas McIlroy, Tom Duff, and Fred Cohen have investigated the implications of shell script viruses. They conclude that it is all to easy for even a novice, a "script kiddie", to write one. [1]

Here is yet another reason to learn scripting. Being able to look at and understand scripts may protect your system from being hacked or damaged.



See Marius van Oers' article, Unix Shell Scripting Malware, and also the Denning reference in the bibliography.