📚 OpenRCE is preserved as a read-only archive. Launched at RECon Montreal in 2005. Registration and posting are disabled.








Flag: Tornado! Hurricane!

 Forums >>  Brainstorms - General  >>  How to hook __usercall, __userpurge (__spoils) functions?

Topic created on: November 4, 2010 12:40 CDT by Svisstack .

Hello,

Know anybody something about hooking __usercall type of functions?
I hooking successfully __thiscall, __stdcall and __cdecl calls but this is enough for me.

Know anybody hooking library for __usercall's or how to hook this type of functions using translation to __stdcall or __cdecl?

Function who i must hook at first is:

int __usercall func<eax>(int a<eax>, int b<ecx>, int c, unsigned int d, signed int e);

  Sirmabus     November 7, 2010 02:58.32 CST
A lot of such calling conventions, as well as targets with processes that are compiled with "Profile Guided Optimization", etc., because arguments might be passed in registers, and maybe registers like ESI that need to remain from one function to the next.

AFAIK (and I do look) there is no generic hooking system that will handle these.
You will have to know how the calling convention works, probably have to study each function, etc.
Then use your own custom ASM stubs that does a "PUSHAD"/"POPAD" to maintain register contexts et al.

Note: Registration is required to post to the forums.

There are 31,328 total registered users.


Recently Created Topics
[help] Unpacking VMP...
Mar/12
Reverse Engineering ...
Jul/06
let 'IDAPython' impo...
Sep/24
set 'IDAPython' as t...
Sep/24
GuessType return une...
Sep/20
About retrieving the...
Sep/07
How to find specific...
Aug/15
How to get data depe...
Jul/07
Identify RVA data in...
May/06
Question about memor...
Dec/12


Recent Forum Posts
Finding the procedur...
rolEYder
Question about debbu...
rolEYder
Identify RVA data in...
sohlow
let 'IDAPython' impo...
sohlow
How to find specific...
hackgreti
Problem with ollydbg
sh3dow
How can I write olly...
sh3dow
New LoadMAP plugin v...
mefisto...
Intel pin in loaded ...
djnemo
OOP_RE tool available?
Bl4ckm4n


Recent Blog Entries
halsten
Mar/14
Breaking IonCUBE VM

oleavr
Oct/24
Anatomy of a code tracer

hasherezade
Sep/24
IAT Patcher - new tool for ...

oleavr
Aug/27
CryptoShark: code tracer ba...

oleavr
Jun/25
Build a debugger in 5 minutes

More ...


Recent Blog Comments
nieo on:
Mar/22
IAT Patcher - new tool for ...

djnemo on:
Nov/17
Kernel debugger vs user mod...

acel on:
Nov/14
Kernel debugger vs user mod...

pedram on:
Dec/21
frida.github.io: scriptable...

capadleman on:
Jun/19
Using NtCreateThreadEx for ...

More ...


Imagery
SoySauce Blueprint
Jun 6, 2008

[+] expand

View Gallery (11) / Submit