mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-30 15:05:27 +00:00
68 lines
931 B
NASM
68 lines
931 B
NASM
|
|
|||
|
|
; A pseudo random numbers generator
|
|||
|
|
; for use with the MuTation Engine <tm>
|
|||
|
|
|
|||
|
|
; Version 1.01 (26-10-91)
|
|||
|
|
; (C) 1991 CrazySoft, Inc.
|
|||
|
|
|
|||
|
|
.model tiny
|
|||
|
|
.code
|
|||
|
|
|
|||
|
|
public rnd_init, rnd_get, rnd_buf, data_top
|
|||
|
|
|
|||
|
|
rnd_init:
|
|||
|
|
push ds si dx cx bx
|
|||
|
|
xor ah,ah
|
|||
|
|
int 1ah
|
|||
|
|
in al,[40h]
|
|||
|
|
mov ah,al
|
|||
|
|
in al,[40h]
|
|||
|
|
xor ax,cx
|
|||
|
|
xor dx,ax
|
|||
|
|
push cs
|
|||
|
|
pop ds
|
|||
|
|
mov si,offset rnd_buf
|
|||
|
|
xor bh,bh
|
|||
|
|
jmp short rnd_put
|
|||
|
|
rnd_get:
|
|||
|
|
push ds si dx cx bx
|
|||
|
|
push cs
|
|||
|
|
pop ds
|
|||
|
|
mov si,offset rnd_buf
|
|||
|
|
mov bl,[si]
|
|||
|
|
xor bh,bh
|
|||
|
|
mov ax,[bx+si+2]
|
|||
|
|
mov dx,[bx+si+4]
|
|||
|
|
add byte ptr [si],4
|
|||
|
|
mov cx,7
|
|||
|
|
rnd_lup:
|
|||
|
|
shl ax,1
|
|||
|
|
rcl dx,1
|
|||
|
|
mov bl,al
|
|||
|
|
xor bl,dh
|
|||
|
|
jns nxt_bit
|
|||
|
|
inc al
|
|||
|
|
nxt_bit:
|
|||
|
|
loop rnd_lup
|
|||
|
|
rnd_put:
|
|||
|
|
mov bl,[si+1]
|
|||
|
|
mov [bx+si+2],ax
|
|||
|
|
mov [bx+si+4],dx
|
|||
|
|
add bl,4
|
|||
|
|
mov [si+1],bl
|
|||
|
|
mov al,dl
|
|||
|
|
cmp bl,[si]
|
|||
|
|
jnz rnd_done
|
|||
|
|
add byte ptr [si],4
|
|||
|
|
rnd_done:
|
|||
|
|
pop bx cx dx si ds
|
|||
|
|
ret
|
|||
|
|
|
|||
|
|
.data
|
|||
|
|
|
|||
|
|
rnd_buf dw 129 dup(?)
|
|||
|
|
|
|||
|
|
data_top:
|
|||
|
|
|
|||
|
|
end
|
|||
|
|
|