I’m releasing my VMProtect devirtualizer for others to research, learn, and improve. This project started in 2018 as a hobby project and was rewritten at least 4 times.
During my research, I’ve met with awesome people, made friends, and learned a lot. The tool is for educational purposes only, it works for vmprotect < 3.8 but produces less than ideal output.
The tool uses Triton for emulation, symbolic execution, and lifting. The easiest way to match VM handlers is to match them on the Triton AST level.
The tool symbolizes vip and vsp registers and propagates memory loads and stores. Almost every handler ends with the store (to the stack, vm register or memory). We take Triton AST of the value that is being stored and match against known patterns:
// Match [vsp] + [vsp].
//
static bool match_add(const triton::ast::SharedAbstractNode& ast)
{
if (ast->getType() == triton::ast::EXTRACT_NODE)
{
return match_add(ast->getChildren()[2]->getChildren()[1]);
}
return ast->getType() == triton::ast::BVADD_NODE
&& is_variable(ast->getChildren()[1], variable::vsp_fetch);
}
No matter how obfuscated handlers are, it is possible to match them with a single x86 instruction! Once the handler is identified, it is lifted into a basic block.
Once the basic block is terminated, the partial control-flow graph is computed and the RIP register is sliced, giving the address of the next basic block.
The process repeats until no new basic blocks are found. Every basic block is lifted into separate LLVM function. The process of building control-flow graph comes down chaining calls to basic block functions in the right order.
The tool has few custom LLVM passes like no-alias
and memory coalescing
passes. The only pass that is left to implement is flag synthesis
pass which will give the cleanest LLVM bitcode.
The tool requires 3 arguments:
./build/titan
titan: for the -i option: must be specified at least once!
titan: for the -b option: must be specified at least once!
titan: for the -e option: must be specified at least once!
./build/titan -i intrinsics/vmprotect64.ll -b samples/loop_hash.0x140103FF4.exe -e 0x140103FF4
Kali Linux 2024.4, the final release of 2024, brings a wide range of updates and…
This Go program applies a lifetime patch to PowerShell to disable ETW (Event Tracing for…
GPOHunter is a comprehensive tool designed to analyze and identify security misconfigurations in Active Directory…
Across small-to-medium enterprises (SMEs) and managed service providers (MSPs), the top priority for cybersecurity leaders…
The free and open-source security platform SecHub, provides a central API to test software with…
Don't worry if there are any bugs in the tool, we will try to fix…