Collaborative RCE Tool Library - Deobfuscation Tools

Tool Updated: CodeDoctor

Thu, 12 Nov 2009 16:24:49 GMT

Listed in categories: Deobfuscation Tools, IDA Extensions, OllyDbg Extensions, Resource Editors, Unpacking Tools

Most recent version:
0.90

Most recent release date:
November 12, 2009

Description:
<nowiki>CodeDoctor is a plugin for Olly and IDA.

History:
11.11.2009 - 0.90 - initial public release

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Functions:

1) Deobfuscate

Select instructions in disasm window and execute this command. It will try
to clear the code from junk instructions.

Example:

Original:
00874372 57 PUSH EDI
00874373 BF 352AAF6A MOV EDI,6AAF2A35
00874378 81E7 0D152A41 AND EDI,412A150D
0087437E 81F7 01002A40 XOR EDI,402A0001
00874384 01FB ADD EBX,EDI
00874386 5F POP EDI

Deobfuscated:
00874372 83C3 04 ADD EBX,4

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2) Deobfuscate - Single Step

This works like previous command, but does one transformation at a time
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3) Move NOPs to bottom

Converts this:

00874396 50 PUSH EAX
00874397 90 NOP
00874398 90 NOP
00874399 52 PUSH EDX
0087439A BA 3F976B00 MOV EDX,somesoft.006B973F

to this:

00874396 50 PUSH EAX
00874397 52 PUSH EDX
00874398 BA 3F976B00 MOV EDX,somesoft.006B973F
0087439D 90 NOP
0087439E 90 NOP

Limitations: it breaks all jumps and calls pointing inwards
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4) Undo / Redo

Undo or Redo last operation (from one of the above functions)

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5) Retrieve Jumpy function

This will statically parse instructions and follow all jumps. This is useful
for situations, when program jumps here and there and here and there... When
it encounters some instruction, that can't be followed, it stop and copies
all parsed instruction to an allocated place in memory.

Use settings to set some parameters:
Step over calls - if set, it will step over calls, otherwise it will follow them
Step over jccs - dtto, but for Jccs
Deobfuscate - it will deobfuscate instruction, when it encounters Jcc, RET,
JMP reg/exp, CALL reg/exp; useful for multi-branch

Example:

Original:
00874389 /EB 05 JMP SHORT somesoft.00874390
0087438B

Tool Added: Windows Script Decoder

Thu, 12 Jun 2008 17:58:53 GMT

Listed in categories: Automated Unpackers, Deobfuscation Tools

Most recent version:
1.8

Most recent release date:
April 10, 2005

Description:
The Windows Script Encoder (screnc.exe) is a Microsoft tool which can be used to encode your scripts (i.e. JScript, ASP pages, VBScript). Yes: encode, not encrypt. The use of this tool is to be able to prevent people from looking at, or modifying, your scripts. Microsoft recommends using the Script Encoder to obfuscate your ASP pages, so in case your server is compromised the hacker would be unable to find out how your ASP applications work.

The Windows Script Decoder is a tool that I wrote which can be used to decode all scripts that have been encoded with the Windows Script Encoder.

Please note that this program was originally written to demonstrate the ease of a cryptoanalysis attack against a tool like the Windows Script Encoder. Nowadays, script encoding is used often to hide malicious scripting commands and the script decoder can be very useful to uncover the original code. Do not use this tool to violate copyright. That's not what it is meant for.

Tool Updated: Pynary

Tue, 15 Jan 2008 07:13:58 GMT

Listed in categories: Deobfuscation Tools, Diff Tools, Exe Analyzers, Executable Diff Tools, Programming Libraries, Reverse Engineering Frameworks

Most recent version:
0.0.1

Most recent release date:

Description:
pynary will become a powerful platform independent framework for binary code analysis.

The initial goal is to the implementation of function signature matching using graph isomorphism and an extensible 'write-your-own-heuristic' model to allow tweaks for particular targets. It will also identify standard library global constants and structure where possible.

Once the initial goal is achieved, a number of cool features are planned:

* stack frame analysis
* un-inliner
* exception handling parsing/analysis
* 'functionally equivalent' matching
* c++ template function matching
* meta-data transfer between IDBs
* c++ class reconstruction (with/without RTTI)
* ...

This project is still in its infancy, and looking for volunteers.