Phishing - AI Security Technique

In July 2025, Ukrainian authorities reported the emergence of LAMEHUG, a new AI-powered malware attributed to the Russian state-backed threat actor APT28 (also tracked as Forest Blizzard or UAC-0001). LAMEHUG uses a large language model (LLM) to dynamically generate commands on the infected hosts.

The campaign began with a phishing attack leveraging a compromised government email account to deliver a malicious ZIP archive disguised as Appendix.pdf.zip. The archive contained the LAMEHUG malware, a Python-based executable, packed with PyInstaller. When executed, the malware, makes calls to an LLM endpoint to generate malicious from natural language prompts. Dynamically generated commands may make the malware harder to detect. LAMEHUG was configured to collect files from the local system and exfiltrate them.

Adversaries create phishing websites that appear visually similar to legitimate sites. These sites are designed to trick users into entering their credentials, which are then sent to the bad actor. To combat this behavior, security companies utilize AI/ML-based approaches to detect phishing sites and block them in their endpoint security products.

In this incident, adversarial examples were identified in the logs of a commercial machine learning phishing website detection system. The detection system makes an automated block/allow determination from the "phishing score" of an ensemble of image classifiers each responsible for different phishing indicators (visual similarity, input form detection, etc.). The adversarial examples appeared to employ several simple yet effective strategies for manually modifying brand logos in an attempt to evade image classification models. The phishing websites which employed logo modification methods successfully evaded the model responsible detecting brand impersonation via visual similarity. However, the other components of the system successfully flagged the phishing websites.