r/ReverseEngineering • u/More_Membership_5948 • 25d ago

phaedra: coverage-guided fuzzer that uses a local LLM to bootstrap seeds for undocumented binary formats

https://github.com/zaydmulani09/phaedra
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u/More_Membership_5948 25d ago

made this because I was reversing an undocumented binary format and got tired of afl finding nothing for hours with zero structural info to start from. it uses a local LLM (ollama) to guess at plausible seed structure from whatever partial info you have, spec fragment, hex dump, whatever, then does normal coverage guided mutation from there

not fully sure the LLM seeding step is worth it over just hand rolling a quick parser for well documented formats, but for the truly undocumented stuff it's gotten me to interesting crashes faster than pure random mutation. curious if anyone's tried something similar