The malware initiates its attack by communicating with a Command-and-Control (C2) server to exfiltrate data and control the infected machine. Regular updates and feature enhancements keep this threat evolving, highlighting the adaptability of modern threat actors. Its ability to bypass traditional defenses while targeting critical data underscores its significance as a serious cybersecurity concern.

Execution and Behavior

The attack process is methodical:

1. Delivery: Typically executed via a drive-by download delivering a malicious ZIP archive. The archive contains an MSI file that contacts the C2 server to retrieve a password for extracting a malicious DLL.

2. DLL Side-Loading: Using legitimate executables (e.g., rnpkeys.exe), the malware loads the payload discreetly.

3. PowerShell Scripts: Encoded scripts decrypt and execute payloads, manipulating data and targeting browser information such as cookies, session data, and credentials.

4. Browser Exploitation: The malware installs a malicious Chrome extension that collects data and manipulates browser behavior to intercept sensitive information like 2FA verification codes.

One notable technique involves using mouse movement patterns to detect "human" activity on the infected machine. This anti-sandbox feature ensures the malware executes only under conditions resembling real user behavior.

Advanced Techniques

LummaC2 Stealer employs a range of advanced evasion methods:

• Obfuscation: Makes reverse engineering difficult by hiding critical code using hashing and encryption.

• Event-Controlled Writes: Files with .scif extensions are written conditionally, revealing content only when specific triggers occur.

• Anti-Debugging: Prevents analysis by dynamically detecting and thwarting debugging tools.

• Fake Websites: Poses as legitimate antivirus software to distribute malicious payloads.