Fungus Posted April 12, 2007 Posted April 12, 2007 (edited) Hi All, I was wondering if someone could have a look at my src and tell help figure out what I have done wrong or am missing with my plugin code. :EDIT: the dialog boxes don't appear correctly, and the patch just crashes olly when he tries to load a file. here is the src. It is in masm and winasm studio. It is a plugin to patch GetSystemTime, to hide olly from various techniques that read it and do some other things, like int3 or checking how long some code takes to execute. thx Edited April 12, 2007 by Fungus
Angel-55 Posted April 12, 2007 Posted April 12, 2007 (edited) Not much only a little problemi fixed you had inc eax just after xor eax,eax is caused the problem i removed it and the dialog appeares normally now i hope it's working too bro' please check it can you ?!Dialog appeares well now i'am onlychecking why ollydbg crashes so try the attached file and check dialog i'll see the other problem......Source.rar Edited April 12, 2007 by Angel-55
Fungus Posted April 12, 2007 Author Posted April 12, 2007 Angel-55: thanks alot! Will check immediate It's my first serious x86 code, so I really appreciate your help very much.
Fungus Posted April 12, 2007 Author Posted April 12, 2007 Its nice that you share your source code Fungus zako; glad to , aren't we supposed to be helping each other here? Ok, here is my newest src (deleted the previous) ok, I got it working, but it only patches GetSystemTime in Olly's Process, not in the Debugged Process. Any clues? src.rar thx
Angel-55 Posted April 12, 2007 Posted April 12, 2007 Fungus can you explain more pleasei don't understand what you mean 100% so a bit more explaination is better and anytarget to try it with the plugin ?? "CrackMe or similar"thanx' in advanced and congratulations for your working Plugin "nice work bro' keep it" !!Cheers
MOID Posted April 12, 2007 Posted April 12, 2007 Because GetSystemTime is pretty constant in all apps, you can get the address of it with GetProcAddress. If you want you can even get the patch addresses from Olly's context. Then, to patch the code in the debuggee you can use Writememory.
Fungus Posted April 12, 2007 Author Posted April 12, 2007 Angel 55: oh like xADT, it has a plugin for GetSystemTime and int, it sets SEH, invokes GetSystemTime, executes an int3, then invokes GetSystemTime again, and subtracts the results from each other, if seconds > 0, then I am being debugged. MOID: do you have an example to use writememory for this? thx
Guest shot Posted April 13, 2007 Posted April 13, 2007 I cant download the src i get an errorThe error returned was:Sorry, some required files are missing, if you intended to view a topic, it's possible that it's been moved or deleted. Please go back and try again.any clue on why this is?
Fungus Posted April 14, 2007 Author Posted April 14, 2007 (edited) Because Teddy changed host yesterday or so, and there is bound to be some errors I can ul somewhere if you wanna look. I have expanded it to handle GetLocalTime aswell, but I'm still trying to figure out how to set the segment properly, so I write to the debugged process. I checked the src code of Is Debugger Present 1.4, but the way he is setting the segment base isn't making any sense to me I don't understand the assume directive of MASM yet. It looks like this.... get_byte_location proc push ebx invoke Getcputhreadid .if (eax) invoke Findthread,eax ;retreive thread info assume eax:ptr t_thread push [eax].reg.base[4*4] ;base of FS pop ebx add ebx,30h invoke Readmemory,addr dw_buffer,ebx,4,MM_RESTORE mov eax,dw_buffer add eax,2h .endif pop ebx ret if someone could explain how it works exactly, that would be really cool. The docs on in the SDK don't say much about Findthread, let alone how to set the segment base. Edited April 14, 2007 by Fungus
Angel-55 Posted April 14, 2007 Posted April 14, 2007 Fungus do you get any errors while using this method ?? if so then could youplease wriet what WinASM says to you and thanx' again .......the IsDebuggerPresent source isn't with mei fsome one could upload it it would be nice and thanx' in advanced and to attach cause there is a problem !!
zako Posted April 14, 2007 Posted April 14, 2007 i fsome one could upload it it would be nice andIts available on the authors home pagehttp://membres.lycos.fr/svtc/
Angel-55 Posted April 14, 2007 Posted April 14, 2007 Sorry Zako i don't know the authoror his page so thanx' bro' for giving a linkreally appreciated thanx' again.........IsDebuggerPresent_Source.rar
Teddy Rogers Posted April 14, 2007 Posted April 14, 2007 Attachments should be working again. Sorry about this folks...Ted.
Angel-55 Posted April 14, 2007 Posted April 14, 2007 Ted. i have one question why doesn't this link work ?? Link: www.tut4you.com and thanx' for fixing the attachment problem it works now perfectly good job !!
Teddy Rogers Posted April 14, 2007 Posted April 14, 2007 Its a spelling mistake, it should be:http://www.tuts4you.com/Ted.
Angel-55 Posted April 14, 2007 Posted April 14, 2007 (edited) No Ted. it's a writting mistake it still doesn't work check it your self here i get this message !! "This directory no longer exists, please go to: http://www.tuts4you.com/" I go to that ink and same message like a loop "Endless One" do you mind checkign it please and thanx' Edited April 14, 2007 by Angel-55
Teddy Rogers Posted April 14, 2007 Posted April 14, 2007 Maybe a DNS between you and the host still needs to be updated. It looks to me from the link you are trying to go to:http://www.tuts4you.com/%22Which, is a directory that does not exist.If you want to continue this it may be better to start a new topic in Site Bug Reports forum...Ted.
Fungus Posted April 14, 2007 Author Posted April 14, 2007 Angel: I haven't tried it yet, I don't understand how the segment base works (guess I spoke too soon in another thread eh?) I keep researching until I figure it out...
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