Callfuscated

hackthebox

Task: heavily obfuscated x86-64 crackme (VM + MBA + opaque predicates + junk instructions) that validates a deterministic password which is itself the flag. Solution: ignore the static obfuscation, attach a gdb oracle to the binary via the qemu-user gdbstub, break at the final test instruction, and brute-force each input byte against the zeroing of its result lane — solving each 4-byte block LSB-first to defeat carry propagation.