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Posts Tagged ‘asm’

WoWMimic v49

June 5th, 2009

WoWMimic v49 is out, a very quick bugfix release.

Nothing has changed in terms of anti-detection (so WardenMimic still works), but amusingly, they introduced a bug into their (recently removed) GetCursorPos and SetCursorPos hook subs for VEH.

They have removed a line from both that compares an internal flag to 1/0. What’s amusing about it is, they left in a conditional jump that relied on that line. That conditional jump will now fire based off the line above (a SUB instruction, which like CMP sets the ZF), and the jump will never be taken. Why is this amusing? Because its proof that the devs wrote the code using inline assemby. I was moderately sure of this before (due to the use of PUSHAD, POPAD, etc), but now we have confirmation. Not only is it totally unneeded to do all that crap in inline ASM, but it also explains that they did in fact implement the obfuscation code manually (mentioned in a previous post), obviously thinking it posed some kind of barrier.

Sorry guys, but it probably took me less time to undo it than it took you to figure it out and write it. REALLY obvious job. The call/pop trick is one of the oldest in the book, literally. C’mon. Raise the bar and give us something fun and challenging to play with. (Yeah I know, I’m asking for the world from these guys)

P.S. Still can’t figure out how to stop detection by WardenMimic?

WoWMimic v47 Changes

May 27th, 2009

Many of you will know by now that WoWMimic v47 is out. A few interesting changes, nothing really substantial though.

  1. GetCursorPos and SetCursorPos are now also hooked using VEH.
  2. ZwQueryVirtualMemory is now hooked at the return statement so values are modified AFTER the function is called. They have fixed one hole, but introduced another. Still hooked with VEH.
  3. ZeGetContextThread hook is still present but not longer activated. They have also updated their hook body, fixing one hole, but again, introducing another (see if you can spot it).
  4. They have implemented some VERY lame ‘obfuscation’ attempts. Really quite a poor job, 5 minutes tops to figure out the mess, or 30 or so seconds if you know what you’re looking at.

All in all quite disappointing. They broke the previous version of WardenMimic but only because they changed the offset at which they were hooking, and I was being nice and lowering the false positive rate by putting in lots of checks to detect only that exact build. Anyway, new WardenMimic incoming soon (when I don’t feel lazy).

Update:

Thanks to Harko for pointing out that GetCursorPos and SetCursorPos are still hooked with JMP hooks. It seems they implemented support for it in their VEH but didn’t actually hook it using VEH for some reason. Much like their unused changes to NtGetContextThread. Kinda retarded really….

Full code:

PrivatePaste Copy

; MimicVectoredHandler

169B379E | 55            | PUSH    EBP                         | ; Standard stack frame setup

169B379F | 8BEC          | MOV     EBP, ESP                    | ; Standard stack frame setup

169B37A1 | 81C4 00FFFFFF | ADD     ESP, -100                   | ; Sub ESP 100. Room for local variables.

169B37A7 | 60            | PUSHAD                              | ; Preserve all registers

169B37A8 | E8 00000000   | CALL    169B37AD                    | ; Obfuscation. ‘Calls’ next line and pushes the address of that line onto stack.

169B37AD | 5B            | POP     EBX                         | ; Pop address (of current line) back off and into EBX

169B37AE | 81EB 75164000 | SUB     EBX, 401675                 | ; Subtract 401675 from EBX (169B37AD) (Final: 165B2138)

169B37B4 | 8B75 08       | MOV     ESI, DWORD PTR [EBP+8]      | ; Get pExceptionInfo

169B37B7 | 8B7E 04       | MOV     EDI, DWORD PTR [ESI+4]      | ; Get pExceptionInfo->pContext

169B37BA | 8B36          | MOV     ESI, DWORD PTR [ESI]        | ; Get pExceptionInfo->pExceptionRecord

169B37BC | 8B87 B8000000 | MOV     EAX, DWORD PTR [EDI+B8]     | ; Get EIP

169B37C2 | 3B83 CD104000 | CMP     EAX, DWORD PTR [EBX+4010CD] | ; Compare EIP to address of GetCursorPos.

169B37C8 | 75 0E         | JNZ     169B37D8                    | ; If not equal go to ContinueSearchRet

169B37CA | 8D83 F8164000 | LEA     EAX, DWORD PTR [EBX+4016F8] | ; Get address of GetCursorPos_Hook

169B37D0 | 8987 B8000000 | MOV     DWORD PTR [EDI+B8], EAX     | ; Move address into EIP

169B37D6 | EB 4C         | JMP     169B3824                    | ; Go to ContinueExecRet

169B37D8 | 3B83 D1104000 | CMP     EAX, DWORD PTR [EBX+4010D1] | ; Compare EIP to address of SetCursorPos

169B37DE | 75 0E         | JNZ     169B37EE                    | ; If not equal go to ContinueSearchRet

169B37E0 | 8D83 2D174000 | LEA     EAX, DWORD PTR [EBX+40172D] | ; Get address of SetCursorPos_Hook

169B37E6 | 8987 B8000000 | MOV     DWORD PTR [EDI+B8], EAX     | ; Move address into EIP

169B37EC | EB 36         | JMP     169B3824                    | ; Go to ContinueExecRet

169B37EE | 3B83 84134000 | CMP     EAX, DWORD PTR [EBX+401384] | ; Compare EIP to address of ZwQueryVirtualMemory_Retn

169B37F4 | 75 0E         | JNZ     169B3804                    | ; If not equal go to ContinueSearchRet

169B37F6 | 8D83 50174000 | LEA     EAX, DWORD PTR [EBX+401750] | ; Get address of ZwQueryVirtualMemory_Hook

169B37FC | 8987 B8000000 | MOV     DWORD PTR [EDI+B8], EAX     | ; Move address into EIP

169B3802 | EB 20         | JMP     169B3824                    | ; Go to ContinueExecRet

169B3804 | 3B83 8C134000 | CMP     EAX, DWORD PTR [EBX+40138C] | ; Compare EIP to address of ZwGetContextThread_Hook. Currently not used/enabled.

169B380A | 75 0E         | JNZ     169B381A                    | ; If not equal go to ContinueSearchRet

169B380C | 8D83 88174000 | LEA     EAX, DWORD PTR [EBX+401788] | ; Get address of ZwGetContextThread_Hook.

169B3812 | 8987 B8000000 | MOV     DWORD PTR [EDI+B8], EAX     | ; Move address into EIP

169B3818 | EB 0A         | JMP     169B3824                    | ; Go to ContinueExecRet

169B381A | 61            | POPAD                               | ; Restore registers

169B381B | B8 00000000   | MOV     EAX, 0                      | ; Move EXCEPTION_CONTINUE_SEARCH into return value

169B3820 | C9            | LEAVE                               | ; Standard function prologue

169B3821 | C2 0400       | RETN    4                           | ; Return

169B3824 | 61            | POPAD                               | ; Restore registers

169B3825 | B8 FFFFFFFF   | MOV     EAX, -1                     | ; Move EXCEPTION_CONTINUE_EXECUTION into return value

169B382A | C9            | LEAVE                               | ; Standard function prolugue

169B382B | C2 0400       | RETN    4                           | ; Return

; GetCursorPos_Hook

169B3830 | E8 00000000      | CALL    169B3835                    | ; Obfuscation. ‘Calls’ next line and pushes the address of that line onto stack.

169B3835 | 5A               | POP     EDX                         | ; Pop address (of current line) back off and into EDX

169B3836 | 81EA FD164000    | SUB     EDX, 4016FD                 | ; Subtract 4016FD from EDX (169B3835) (Final: 165B2138)

169B383C | 83BA 09104000 01 | CMP     DWORD PTR [EDX+401009], 1   | ; Compare some internal flag to 1

169B3843 | 75 15            | JNZ     169B385A                    | ;

169B3845 | 8B4C24 04        | MOV     ECX, DWORD PTR [ESP+4]      | ; Get lpPoint

169B3849 | 8B82 0D104000    | MOV     EAX, DWORD PTR [EDX+40100D] | ; Get custom mouse x

169B384F | 8901             | MOV     DWORD PTR [ECX], EAX        | ; Set lpPoint->x to custom mouse x

169B3851 | 8B82 11104000    | MOV     EAX, DWORD PTR [EDX+401011] | ; Get custom mouse y

169B3857 | 8941 04          | MOV     DWORD PTR [ECX+4], EAX      | ; Set lpPoint->y to custom mouse y

169B385A | 8B82 CD104000    | MOV     EAX, DWORD PTR [EDX+4010CD] | ; Get address of GetCursorPos

169B3860 | 83C0 02          | ADD     EAX, 2                      | ; Jump over invalid instruction

169B3863 | FFE0             | JMP     NEAR EAX                    | ; Jump to GetCursorPos (+2)

; SetCursorPos_Hook

169B3865 | E8 00000000      | CALL    169B386A                    | ; Obfuscation. ‘Calls’ next line and pushes the address of that line onto stack.

169B386A | 5A               | POP     EDX                         | ; Pop address (of current line) back off and into EDX

169B386B | 81EA 32174000    | SUB     EDX, 401732                 | ; Subtract 401732 from EDX (169B386A) (Final: 165B2138)

169B3871 | 83BA 09104000 01 | CMP     DWORD PTR [EDX+401009], 1   | ; Compare some internal flag to 1

169B3878 | 75 03            | JNZ     169B387D                    | ; Jump if not equal to RetnCallOrig

169B387A | C2 0800          | RETN    8                           | ; Return without calling original

169B387D | 8B82 D1104000    | MOV     EAX, DWORD PTR [EDX+4010D1] | ; Get address of SetCursorPos

169B3883 | 83C0 02          | ADD     EAX, 2                      | ; Jump over invalid instruction

169B3886 | FFE0             | JMP     NEAR EAX                    | ; Jump to SetCursorPos (+2)

; ZwQueryVirtualMemory_Hook

169B3888 | E8 00000000      | CALL    169B388D                    | ; Obfuscation. ‘Calls’ next line and pushes the address of that line onto stack.

169B388D | 5A               | POP     EDX                         | ; Pop address (of current line) back off and into EDX

169B388E | 81EA 55174000    | SUB     EDX, 401755                 | ; Subtract 401755 from EDX (169B388D) (Final: 165B2138)

169B3894 | 50               | PUSH    EAX                         | ; Preserve EAX

169B3895 | 8B4424 14        | MOV     EAX, DWORD PTR [ESP+14]     | ; Get pMemoryBasicInformation

169B3899 | 8B48 04          | MOV     ECX, DWORD PTR [EAX+4]      | ; Get pMemoryBasicInformation->Allocationbase

169B389C | 3B8A 21104000    | CMP     ECX, DWORD PTR [EDX+401021] | ; Compare to MimicModuleBase

169B38A2 | 75 18            | JNZ     169B38BC                    | ; If not equal jump to LocRetn

169B38A4 | C700 00000000    | MOV     DWORD PTR [EAX], 0          | ; Zero out pMemoryBasicInformation->BaseAddress

169B38AA | C740 04 00000000 | MOV     DWORD PTR [EAX+4], 0        | ; Zero out pMemoryBasicInformation->AllocationBase

169B38B1 | C740 10 00000100 | MOV     DWORD PTR [EAX+10], 10000   | ; Set pMemoryBasicInformation->State to MEM_FREE

169B38B8 | 58               | POP     EAX                         | ; Restore EAX

169B38B9 | C2 1800          | RETN    18                          | ; Return

169B38BC | 58               | POP     EAX                         | ; Restore EAX

169B38BD | C2 1800          | RETN    18                          | ; Return

; ZwGetContextThread_Hook

169B38C0 | 8B4C24 08        | MOV     ECX, DWORD PTR [ESP+8] | ; Get pContext

169B38C4 | C741 04 00000000 | MOV     DWORD PTR [ECX+4], 0   | ; Zero out DR0

169B38CB | C741 08 00000000 | MOV     DWORD PTR [ECX+8], 0   | ; Zero out DR1

169B38D2 | C741 0C 00000000 | MOV     DWORD PTR [ECX+C], 0   | ; Zero out DR2

169B38D9 | C741 10 00000000 | MOV     DWORD PTR [ECX+10], 0  | ; Zero out DR3

169B38E0 | C2 0800          | RETN    8                      | ; Return