Biblio

Compile-time specialization and feature pruning through static binary rewriting have been proposed repeatedly as techniques for reducing the attack surface of large programs, and for minimizing the trusted computing base. We propose a new approach to attack surface reduction: dynamic binary lifting and recompilation. We present BinRec, a binary recompilation framework that lifts binaries to a compiler-level intermediate representation (IR) to allow complex transformations on the captured code. After transformation, BinRec lowers the IR back to a "recovered" binary, which is semantically equivalent to the input binary, but does have its unnecessary features removed. Unlike existing approaches, which are mostly based on static analysis and rewriting, our framework analyzes and lifts binaries dynamically. The crucial advantage is that we can not only observe the full program including all of its dependencies, but we can also determine which program features the end-user actually uses. We evaluate the correctness and performance of BinRec, and show that our approach enables aggressive pruning of unwanted features in COTS binaries.

Existing anti-debugging protections are relatively weak. In existing self-debugger approaches, a custom debugger is attached to the main application, of which the control flow is obfuscated by redirecting it through the debugger. The coupling between the debugger and the main application is then quite loose, and not that hard to break by an attacker. In the tightly-coupled self-debugging technique proposed in this paper, full code fragments are migrated from the application to the debugger, making it harder for the attacker to reverse-engineer the program and to deconstruct it into the original unprotected program to attach a debugger or to collect traces. We evaluate a prototype implementation on three complex, real-world Android use cases and present the results of tests conducted by professional penetration testers.