All Writeups

Comprehensive collection of CTF challenges, solutions, and insights.

2026-03-01 Forensics Hard

DEADROP Forensics 4 - Redacted Blueprint

A PDF floor plan whose rooms spell OOPS from above, hiding a flag in an orphaned FlateDecode XObject with no page tree reference, invisible to all standard PDF viewers. Requires parsing raw PDF streams or hex editing to find and base64-decode the hidden object.

forensics pdf xobject streams

2026-03-01 Forensics Medium

DEADROP Forensics 3 - svchost_1337

An ELF core dump with a flag encoded through four layers, ROT13, base64, hex, and XOR 0x7d, hidden in the NT_PRPSINFO note section. readelf -n and working backwards through each encoding layer recovers it.

forensics core-dump elf readelf