手脱nSPack 1.3

1.PEID查壳

nSPack 1.3 -> North Star/Liu Xing Ping

2.载入OD，pushad下面的call哪里使用ESP定律，下硬件访问断点，然后shift+F9运行

00432356 >  9C              pushfd                            ; //程序入口点
00432357    60              pushad
00432358    E8 00000000     call QQ个性网.0043235D            ; //这里使用ESP
0043235D    5D              pop ebp                           
0043235E    B8 B3854000     mov eax,QQ个性网.004085B3
00432363    2D AC854000     sub eax,QQ个性网.004085AC
00432368    2BE8            sub ebp,eax                       
0043236A    8DB5 D6FEFFFF   lea esi,dword ptr ss:[ebp-0x12A]

 

3.ESP落脚点，落脚点的下一行就是一个大跳转，就是跳向OEP的，F8单步跟着跳

0043257A    9D              popfd                             ; //ESP落脚点
0043257B  - E9 54EDFCFF     jmp QQ个性网.004012D4             ; //跳向OEP的大跳转
00432580    8BB5 AEFEFFFF   mov esi,dword ptr ss:[ebp-0x152]
00432586    0BF6            or esi,esi
00432588    0F84 97000000   je QQ个性网.00432625

 

4.来到OEP，可以脱壳了

004012D4    68 54474000     push QQ个性网.00404754               ; //来到OEP
004012D9    E8 F0FFFFFF     call QQ个性网.004012CE               
004012DE    0000            add byte ptr ds:[eax],al
004012E0    0000            add byte ptr ds:[eax],al
004012E2    0000            add byte ptr ds:[eax],al
004012E4    3000            xor byte ptr ds:[eax],al
004012E6    0000            add byte ptr ds:[eax],al
004012E8    48              dec eax    

 

5.查壳运行

运行OK，查壳：Microsoft Visual Basic v5.0/v6.0