https://th3b0ywh0l1v3d.github.io/categories/reversing/ Recent content in Reversing on Th3B0yWh0L1v3d — Security Writeups Hugo en-us Tue, 16 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/alphacode/ Tue, 16 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/alphacode/ Reverse-engineering a custom esolang stack machine to recover the flag. https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/amazing/ Tue, 16 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/amazing/ Reversing a Python marshal bytecode maze generator seeded by an LCG to find the escape path. https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/cat/ Tue, 16 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/cat/ Reversing a repeating-key XOR crackme that downloads the flag from catbox.moe. https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/franklin/ Tue, 16 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/franklin/ Recovering the flag from TrueType GSUB ligature substitution rules. https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/george-orwell/ Tue, 16 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/george-orwell/ Decompiling a compiled AutoHotkey executable to extract the flag. https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/hidden-but-definitely-not/ Tue, 16 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/hidden-but-definitely-not/ Recovering a flag hidden via stack-string construction and XOR obfuscation. https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/not-your-time/ Tue, 16 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/not-your-time/ Crackme that stores the bitwise NOT of the flag bytes; invert them to get the flag. https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/perfectly-destructive-file/ Tue, 16 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/boroctf-2026/reversing/perfectly-destructive-file/ Extracting a flag hidden inside a PDF stream using FlateDecode and base64. https://th3b0ywh0l1v3d.github.io/ctf/dalctf-2026/reversing/baby-android/ Sat, 06 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/dalctf-2026/reversing/baby-android/ A single APK whose UI claims there’s nothing to see — the flag is split into three pieces hidden in a MainActivity field, a string resource, and a Compose theme getter. https://th3b0ywh0l1v3d.github.io/ctf/dalctf-2026/reversing/bit-miner/ Sat, 06 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/dalctf-2026/reversing/bit-miner/ An idle/clicker TCP game whose shop checks affordability against a stale cached balance but deducts from a fresh re-read; racing two sessions as the same user underflows an unsigned long to ~1.8e19 bits and buys the flag. https://th3b0ywh0l1v3d.github.io/ctf/dalctf-2026/reversing/do-you-know-the-way/ Sat, 06 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/dalctf-2026/reversing/do-you-know-the-way/ A UPX-packed, unstripped crackme lays its 44-byte check out as 44 independent per-character functions; emulating each with Unicorn brute-forces the flag one byte at a time, sidestepping a rand()-based anti-dynamic trap. https://th3b0ywh0l1v3d.github.io/ctf/dalctf-2026/reversing/haskell2/ Sat, 06 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/dalctf-2026/reversing/haskell2/ A stripped compiler for an invented language is reverse-engineered from its error strings and codegen templates; the recovered grammar exposes an intended read file primitive that simply prints flag.txt — no exploit required. https://th3b0ywh0l1v3d.github.io/ctf/gpn-ctf-2026/reversing/konigsberg-delivery-problem/ Fri, 05 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/gpn-ctf-2026/reversing/konigsberg-delivery-problem/ Reversing a 250-state control-flow-flattened automaton whose success check requires visiting every state — i.e. finding a Hamiltonian path through the transition graph. https://th3b0ywh0l1v3d.github.io/ctf/gpn-ctf-2026/reversing/leftover-leftovers/ Fri, 05 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/gpn-ctf-2026/reversing/leftover-leftovers/ A two-stage Java AOT-cache app whose integrity hash covers bytecode and pointers but not the archived heap — patching the pre-resolved heap String redirects the image directory and reads /flag. https://th3b0ywh0l1v3d.github.io/ctf/gpn-ctf-2026/reversing/leftovers/ Fri, 05 Jun 2026 00:00:00 +0000 https://th3b0ywh0l1v3d.github.io/ctf/gpn-ctf-2026/reversing/leftovers/ Reversing a Javalin app whose real password validator lives in an AOT/CDS cache that overrides the jar — dumping the loaded class with the HotSpot Serviceability Agent unlocks a file-read to /flag.