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Having trouble with some code

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Having trouble with some code

 #16932  by RageMachine
 Fri Nov 30, 2012 4:34 pm
I'm having some trouble with a piece of malware I'm trying to work with, the main issue is that it manages to always terminate outside the user code. When I run it normally under BSA, it runs and terminates like so:
Code: Select all
LoadLibrary(uxtheme.dll) [c:\documents and settings\not_a_vm\yuksfgiluegwufywpcjt.exe]
IsDebuggerPresent() [c:\documents and settings\not_a_vm\yuksfgiluegwufywpcjt.exe]
FreeLibrary(C:\WINDOWS\system32\uxtheme.dll) [c:\documents and settings\not_a_vm\yuksfgiluegwufywpcjt.exe]
Sleep(50) [c:\documents and settings\not_a_vm\yuksfgiluegwufywpcjt.exe]
ExitProcess(0) [c:\documents and settings\not_a_vm\yuksfgiluegwufywpcjt.exe]
OpenProcess(taskmgr.exe) [c:\documents and settings\not_a_vm\yuksfgiluegwufywpcjt.exe]
OpenProcess(hpqtra08.exe) [c:\documents and settings\not_a_vm\yuksfgiluegwufywpcjt.exe]
OpenProcess(wscntfy.exe) [c:\documents and settings\not_a_vm\yuksfgiluegwufywpcjt.exe]
OpenProcess(hpwuSchd2.exe) [c:\documents and settings\not_a_vm\yuksfgiluegwufywpcjt.exe]
GetModuleHandle(EXPLORER.EXE) [c:\documents and settings\not_a_vm\yuksfgiluegwufywpcjt.exe]
I am not sure how to deal with GetModuleHandle as far as BSA is concerned, I cannot see how this would trigger my VM's detection or sandbox detection. Secondly, when I load it into Olly, It always terminates after IsDebuggerPresent even if I modify the return. Sleep works fine, but it seems to just quit at ExitProcess(0). I am not sure how to handle this, I thought it was TLS, and I can see some TLS import when i examine it in CFF Explorer, but the TLS directory and offset are just 00000. If i step through the code for awhile, I can eventually find some code outside the code section, but it so robust It would take weeks to get through it all. Is there some sort of "sweet spot" to look for to prevent termination of this process so I can continue reversing it?
Attachments
pass is my username
(408.61 KiB) Downloaded 56 times
Last edited by RageMachine on Fri Nov 30, 2012 5:48 pm, edited 1 time in total.

Re: Having trouble with some code

 #16933  by EP_X0FF
 Fri Nov 30, 2012 5:25 pm
Telepaths on vacation.

Please attach your malware in password protected archive.

Re: Having trouble with some code

 #16939  by STRELiTZIA
 Sat Dec 01, 2012 9:45 am
Aggressive Fake AV (System progressive protection)
Before infecting the system it checks if c:\mscheck.dbg exists...
Try to create an empty file (c:\mscheck.dbg) and run the malware (wait a few seconds :twisted:)... Tested on VMWare...

Re: Having trouble with some code

 #16950  by RageMachine
 Sat Dec 01, 2012 5:44 pm
STRELiTZIA wrote:Aggressive Fake AV (System progressive protection)
Before infecting the system it checks if c:\mscheck.dbg exists...
Try to create an empty file (c:\mscheck.dbg) and run the malware (wait a few seconds :twisted:)... Tested on VMWare...
Yes, I see that now in procmon! How interesting... I didn't even think to use process monitor when attempting to reverse it. Thank you for the tip!

Thank you as well Xylitol.

With the tips you guys gave me, I was able to use BSA to run the program and then configured it to dump it to disk. Using the dump, I then loaded the malware into Olly, bypassed debugger checks, let it run until OpenProcess(), and then used imprec to fix the original dump. Then I removed the extras. I thank you for your help.

Re: Having trouble with some code

 #16952  by STRELiTZIA
 Sun Dec 02, 2012 9:20 am
Also, take a look on the executables name length on infected machine, all length name equal to 16 can be launched...
e.g: Rename calc.exe to 0123456789ABCDEF.exe then try to launch it.

Re: Having trouble with some code

 #16953  by Tigzy
 Sun Dec 02, 2012 10:19 am
Classic rogue
¤¤¤ Processus malicieux : 1 ¤¤¤
[Rogue.AntiSpy-ST] ACA906A94F43CF610000ACA85A04D33F.exe -- C:\Documents and Settings\All Users\Application Data\ACA906A94F43CF610000ACA85A04D33F\ACA906A94F43CF610000ACA85A04D33F.exe -> TUÉ [TermProc]
[Rogue.AntiSpy-ST][BLACKLIST] ACA906A94F43CF610000ACA85A04D33F.exe -- C:\Documents and Settings\All Users\Application Data\ACA906A94F43CF610000ACA85A04D33F\ACA906A94F43CF610000ACA85A04D33F.exe -> TUÉ [TermThr]

¤¤¤ Entrees de registre : 2 ¤¤¤
[RUN][Rogue.AntiSpy-ST] HKCU\[...]\RunOnce : ACA906A94F43CF610000ACA85A04D33F (C:\Documents and Settings\All Users\Application Data\ACA906A94F43CF610000ACA85A04D33F\ACA906A94F43CF610000ACA85A04D33F.exe) -> TROUVÉ
[RUN][Rogue.AntiSpy-ST] HKUS\S-1-5-21-823518204-842925246-839522115-1003[...]\RunOnce : ACA906A94F43CF610000ACA85A04D33F (C:\Documents and Settings\All Users\Application Data\ACA906A94F43CF610000ACA85A04D33F\ACA906A94F43CF610000ACA85A04D33F.exe) -> TROUVÉ

Re: Having trouble with some code

 #16972  by RageMachine
 Sun Dec 02, 2012 5:52 pm
STRELiTZIA wrote:Also, take a look on the executables name length on infected machine, all length name equal to 16 can be launched...
e.g: Rename calc.exe to 0123456789ABCDEF.exe then try to launch it.
I'm having a blast with these, just searching for little doors all over the code :lol: I get so jazzed up about this stuff.
Although I did my dump and i can see all the code, running the unpacked just terminates -_- but I can still see all that it does. I'm sure im overlooking something.
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