OSINT

CTF open source intelligence challenge writeups by event and year

Open-source intelligence (OSINT) writeups from Google CTF, DEF CON, picoCTF, and other global competitions. Organized by year and event.

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2025 Challenges

Google CTF 2025

Google CTF 2025

WhereIsIt

Easy

Category: OSINT · Points: 100 · Solves: 630

Identify the exact name of a building visible in a cropped image featuring a reflective glass facade. Locate the coordinates and find the town name.

GeolocationImage Reverse SearchReflections

Writeup →

picoCTF 2025

picoCTF 2025

Satellite

Medium

Category: OSINT · Points: 180 · Solves: 280

Given a set of orbital parameters and a time window, find the name of the military vessel that passed closest to a specified research base.

Satellite TrackingCoordinate AnalysisOpenDataMarineTraffic

Writeup →