SWIMMER CTF OSINT Writeup: Advanced Image Forensics, AI Decoy Detection, and Real-World Attributionon open source intelligence.
This writeup presents a comprehensive solution to the SWIMMER OSINT CTF, covering multiple challenges involving image verification,social media osint, AI-generated decoy detection, metadata analysis, geolocation, and attribution. The investigation demonstrates how modern OSINT challenges intentionally exploit overreliance on EXIF data and visual assumptions by embedding AIGC fingerprints and misleading context. By combining automated metadata extraction, AI provenance detection, reverse image search, and human-centric reasoning, the correct signals were isolated and verified. This case study highlights practical OSINT techniques required to operate effectively in an era of synthetic media and increasingly deceptive open-source artifacts.
Jan 17, 2026