Steganography: Hiding Secrets in Plain Sight

The Art of Hidden Writing

Cryptography scrambles a message so it can't be read. Steganography hides the message so it can't be seen. In the digital age, this means embedding malicious code or stolen data inside harmless files like JPEGs, PNGs, or MP3s.

Malicious Use Cases

1. Malware Delivery: A user downloads a funny meme image. Hidden in the pixel data is a script that executes when the image is loaded by a vulnerable viewer.
2. Data Exfiltration: An insider steals sensitive documents, hides them inside photos of their cat, and emails them out. DLP (Data Loss Prevention) systems see only images and let them pass.
3. C2 Communication: Botnets receive commands hidden in images posted on public social media profiles.

Detecting Steganography (Steganalysis)

• Statistical Analysis: Looking for statistical anomalies in the file's data structure.
• File Integrity: Comparing the file hash against known good versions.
• Traffic Analysis: Monitoring for unusually large image files or frequent downloads from specific sources.

Related Reading

• Data Exfiltration Prevention
• Insider Threat Detection
• Social Engineering Tactics
• Botnets Explained
• Threat Hunting Guide