hrtng

hrtng IDA plugin

hrtng IDA plugin is a collection of tools, ideas and experiments from different sources I've found interesting and useful in my reversing work.

A practical guide to the reverse of a complex malware using the example of dissecting a FinSpy module with help of hrtng IDA plugin on securelist

There is no one place in menu where all functionality of the plugin grouped together. hrtng menu items placed closer to logically related standard IDA & Hex-Rays decompiler functions. Messages, menu items, popup windows and dialog boxes belong to this plugin are marked with "[hrt]" prefix.

The plugin requires Hex-Rays decompiler presence in your IDA installation. The plugin can be compiled with IDA SDK >= 7.3 but not well tested with old versions.

Special thanks to following peoples for their great plugins were used as base for my work:

• Milan Bohacek, hexrays_tools and hexrays_hlight
• HexRaysDeob by Rolf Rolles and Takahiro Haruyama
• Karthik Selvaraj Krypton plugin
• Ali Rahbar, Ali Pezeshk and Elias Bachaalany GraphSlick plugin
• Markus Gaasedelen AVX support for the Hex-Rays x64 Decompiler

Features of the plugin:

Automation

• Pull up comments from disasm to pseudocode view
• Automatic renaming local and global variables, struct members
• Automatic enum substitution
• COM helper

Interactive pseudocode transformation

• User interactive renaming/retyping assistance
• Assists with changing type of structure member or local/global variable
• reinterpret_cast
• Collapse selection
• "offsetof" convertor

Decryption

• Strings/data/const decryption
• Build stack strings (optionally with decryption)
• Build array strings (optionally with decryption)
• Mass strings decryption

Deal with obfuscated code

• Decompile obfuscated code
• Scan for API names hashes
• Unflattening

Code recognition

• Microcode signatures
• De-Inline - detection of inlined functions

Structures assistance

• Create dummy structs
• Assist split gaps in structures

Virtual/indirect calls assistance

• Virtual calls assistance
• Jump to indirect call destination
• Fix stack pointer for indirect call

IDA UI improvements

• Extended xrefs
• Matching brace highlight
• Auto turn on 'Functions' window content synchronisation

Misk features

• Get API help
• AVX lifter
• Dump strings, comments and names from the IDA database
• Offsets table creation
• Convert function to __usercall, detect spoiled registers
• Set calling conventions bit closer to Go-lang

Patching

• Patch custom area with NOPs
• Patch from debugger / Patch from file
• Search & Patch
• Create patched (DEC) file

IDA plugin developer help

• Microcode Explorer

Building

• Clone or download Crypto++® Library CMake source code to hrtng/src/cryptopp-cmake folder.

cd src
git clone https://github.com/abdes/cryptopp-cmake

• Copy IDA_DIR/plugins/hexrays_sdk/include/hexrays.hpp file to the include directory of the IDA SDK. (Not necessary for IDA 9.0)
• Edit hrtng/src/CMakeLists.txt file to set correct path and version of used IDA SDK. To build later with another SDK version you may change cmake's IDASDK_VER variable with using cmake -D, ccmake or cmake-gui tools.
• Create build directory, go into it, configure and build cmake project

mkdir bld && cd bld
cmake <path-to/hrtng/src>
cmake --build . --config Release -j 4 --clean-first

• On the first build attempt there will be compiling error looks like:

hrtng/src/deob.cpp:912:60: error: ‘class rangeset_t’ has no member named ‘getbag’
     fc.create("tmpfc2", ranges.getbag(), 0);//!!! add line into range.hpp, class rangeset_t: "const rangevec_t &getbag() const { return bag; }"

• To fix the error, edit IDA_SDK/include/range.hpp file, adding line with getbag function implementation into class rangeset_t declaration as in the following example:

class rangeset_t
{
  rangevec_t bag;
  ...
  public:
  const rangevec_t &getbag() const { return bag; }
  ...
};

• Copy built binaries into IDA_DIR/plugins folder togeter with apilist.txt and literal.txt files from hrtng/bin/plugins
• Profit

License

This program is released under GPL v3 license

Authors

• Sergey.Belov at kaspersky.com