Key points
- You can distinguish the command dispatcher from the actual virtual machine: vm_invoke routes commands, while the interpreter at 0x170D1C executes the bytecode.
- The VM uses a direct-threaded design with variable-width instruction slots.
- The analysis reconstructed 214 opcodes, including 133 straight-line handlers, 81 conditional handlers, and 13 handlers containing calls or indirect branches.
Context
The workflow combines DuckDroid traces with streaming instruction matching and lifting to rebuild an intermediate representation from execution. For teams examining legacy systems, the case demonstrates how trace boundaries, nested calls, and native-code transitions must be handled together rather than treated as separate artifacts.
What this means for you
Directly applicable
You can adapt the trace, matcher, and lifter workflow to reconstruct command interpreters and preserve control-flow semantics in complex native binaries.
Who benefits: Developers who maintain, migrate, or integrate legacy native command systems can reuse the trace-based reconstruction method.
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