All Writeups

Comprehensive collection of CTF challenges, solutions, and insights.

2026-05-10 Network Hard

Raptor Weekly 2 - ECHELON Network 2 - 4.2 ; EXFIL

Parsing a custom ECP/1.2 protocol capture, deriving a stream key via HMAC-SHA256 from the Tier 4 handshake key, decrypting three of four signing key chunks, and hunting down the missing chunk in a PCAP from two tiers and two days earlier.

network crypto pcap aes-cbc

2026-05-10 Network Easy

Raptor Weekly 2 - ECHELON Network 1 - 2.1 ; INTERCEPT

Parsing a raw HTTP traffic capture to identify an authenticated session, replaying a stolen token against a restricted endpoint, and reading every response header carefully enough to find a value that won't make sense until Tier 4.

network pcap ECHELON Raptor-Weekly