Ok this bp create thread been bugging me ..
i must have been doing something wrong then i thought about it more...
When i first run the app my first breakpoint create thread landed me in a CALL to CreateThread from RTUTILS..see below
0012E5D8 778321E6 /CALL to CreateThread from RTUTILS.778321E0
0012E5DC 00000000 |pSecurity = NULL
0012E5E0 00000000 |StackSize = 0
0012E5E4 778321FE |ThreadFunction = RTUTILS.778321FE
0012E5E8 00137FA0 |pThreadParm = 00137FA0
0012E5EC 00000000 |CreationFlags = 0
0012E5F0 0012E600 \pThreadId = 0012E600
0012E5F4 77830000 RTUTILS.77830000
I guessing markus means for the creat thread to be called from the main exe so i kept the bp create thread on and F9'D again..after 34 exceptions i break again on CREATE THREAD..see below
0012F568 00A7F26A /CALL to CreateThread from 00A7F264
0012F56C 00000000 |pSecurity = NULL
0012F570 00000000 |StackSize = 0
0012F574 00A7F7FF |ThreadFunction = 00A7F7FF
0012F578 00000000 |pThreadParm = NULL
0012F57C 00000000 |CreationFlags = 0
0012F580 0012F588 \pThreadId = 0012F588
0012F584 004C12C8 vvvVideo.004C12C8
0012F588 00000001
The code i land in is similar to the code from the first break create thread but this time it being called from the main apps exe..which is what i want?
7C57A1EC > 55 PUSH EBP < broke here
7C57A1ED 8BEC MOV EBP,ESP
7C57A1EF FF75 1C PUSH DWORD PTR SS:[EBP+1C]
7C57A1F2 FF75 18 PUSH DWORD PTR SS:[EBP+18]
7C57A1F5 FF75 14 PUSH DWORD PTR SS:[EBP+14]
7C57A1F8 FF75 10 PUSH DWORD PTR SS:[EBP+10]
7C57A1FB FF75 0C PUSH DWORD PTR SS:[EBP+C]
7C57A1FE FF75 08 PUSH DWORD PTR SS:[EBP+8]
7C57A201 6A FF PUSH -1
7C57A203 E8 ACFEFFFF CALL KERNEL32.CreateRemoteThread
7C57A208 5D POP EBP
7C57A209 C2 1800 RETN 18 < F8'd (stepped over) till here then returned
00A7F26A 5E POP ESI ; vvvVideo.004C12C8 < Land here (NOW things are beginning to look like code the others posted above
)
00A7F26B C9 LEAVE
00A7F26C C3 RETN < F8'd to here then returned
00A9709C 6A 00 PUSH 0 < returned to here and looked down and lo and behold i see the magic CALL EDI
)
00A9709E C705 7810AA00 0>MOV DWORD PTR DS:[AA1078],0AA1C04 ; ASCII "RC"
00A970A8 E8 7122FEFF CALL 00A7931E
00A970AD 59 POP ECX
00A970AE 59 POP ECX
00A970AF E8 2F0AFFFF CALL 00A87AE3
00A970B4 8BF8 MOV EDI,EAX
00A970B6 A1 6890AA00 MOV EAX,DWORD PTR DS:[AA9068]
00A970BB 8B48 14 MOV ECX,DWORD PTR DS:[EAX+14]
00A970BE 3348 10 XOR ECX,DWORD PTR DS:[EAX+10]
00A970C1 3348 0C XOR ECX,DWORD PTR DS:[EAX+C]
00A970C4 03F9 ADD EDI,ECX
00A970C6 8B0E MOV ECX,DWORD PTR DS:[ESI]
00A970C8 85C9 TEST ECX,ECX
00A970CA 75 2F JNZ SHORT 00A970FB
00A970CC 8B78 10 MOV EDI,DWORD PTR DS:[EAX+10]
00A970CF E8 0F0AFFFF CALL 00A87AE3
00A970D4 8B0D 6890AA00 MOV ECX,DWORD PTR DS:[AA9068] ; vvvVideo.004BB2A0
00A970DA FF76 14 PUSH DWORD PTR DS:[ESI+14]
00A970DD 8B51 14 MOV EDX,DWORD PTR DS:[ECX+14]
00A970E0 FF76 10 PUSH DWORD PTR DS:[ESI+10]
00A970E3 3351 0C XOR EDX,DWORD PTR DS:[ECX+C]
00A970E6 FF76 0C PUSH DWORD PTR DS:[ESI+C]
00A970E9 33D7 XOR EDX,EDI
00A970EB 03C2 ADD EAX,EDX
00A970ED 8B51 5C MOV EDX,DWORD PTR DS:[ECX+5C]
00A970F0 3351 24 XOR EDX,DWORD PTR DS:[ECX+24]
00A970F3 33D7 XOR EDX,EDI
00A970F5 2BC2 SUB EAX,EDX
00A970F7 FFD0 CALL EAX
00A970F9 EB 25 JMP SHORT 00A97120
00A970FB 83F9 01 CMP ECX,1
00A970FE 75 22 JNZ SHORT 00A97122
00A97100 FF76 04 PUSH DWORD PTR DS:[ESI+4]
00A97103 FF76 08 PUSH DWORD PTR DS:[ESI+8]
00A97106 6A 00 PUSH 0
00A97108 E8 D609FFFF CALL 00A87AE3
00A9710D 50 PUSH EAX
00A9710E A1 6890AA00 MOV EAX,DWORD PTR DS:[AA9068]
00A97113 8B48 5C MOV ECX,DWORD PTR DS:[EAX+5C]
00A97116 3348 24 XOR ECX,DWORD PTR DS:[EAX+24]
00A97119 3348 10 XOR ECX,DWORD PTR DS:[EAX+10]
00A9711C 2BF9 SUB EDI,ECX
00A9711E FFD7 CALL EDI < This call edi according to arma gurus is the call to OEP
...I F8'd to here and F7'D in (stepped into the CALL)
After deciding that maybe this app takes me 2 bp create threads to get CALL EDI instead of 1 i took time out to compare it to the code in other posts and noticed that its IDENTICAL to the code xastey posted except my locations start with "00A" and xastey's is "00B" but apart from that there the same so this just might be the CALL EDI im hoping for...
I also noticed that the codes the same as the code in one of my earlier posts above when i was asking if the code was leading me to the OEP so if this is the CALL TO OEP then id done it ages ago but didnt know it..Im learning though and we learn by our mistakes...
So is this the correct CALL EDI ??...it leads to >>
00453F74 55 PUSH EBP
00453F75 8BEC MOV EBP,ESP
00453F77 6A FF PUSH -1
00453F79 68 20334600 PUSH vvvVideo.00463320
00453F7E 68 26414500 PUSH vvvVideo.00454126 ; JMP to MSVCRT._except_handler3
00453F83 64:A1 00000000 MOV EAX,DWORD PTR FS:[0]
00453F89 50 PUSH EAX
Is 00453F74 the OEP ?..I hope so ..
To dump it i binary edited the
00453F74 55 PUSH EBP >> EBFE "Jump to 00453f74" so that its in a continous loop then dumped it using lord pe ..after dumping i changed the ebfe back to original code and changed the OEP using lord pe's editor to 00053f74 <..is this correct way to do it?
The dumped exe doesnt give me that "bad sector and virus bla bla " msg now which is a good thing ( i think)..
it doesnt run either but thats because ive still to learn to rebuild its IAT table
Ive been told by stephenteh who cracked this after seeing this post that it uses IAT destruction and best way to defeat it is to read RICARDO's tut on arma iat destruction > 205-ARMADILLO CON DESTRUCCION DE TABLA <
stephenteh unpacked earlier version the version im doing is .250 beta
Can someone confirm that ive found OEP so i can leave this part behind and continue on to IAT?...Thanks
Also why does it take me 2 bp create threads to get to CALL EDI?
EDIT..Its ok im lookin at Ricardo's tut on iat destruction and it shows a pic of code at OEP..looks same as above so cool..heres goes iat building now!!
Cheers xastie,
paul333