Cybercriminals have developed a sophisticated campaign using LummaStealer malware combined with deceptive CAPTCHA prompts to harvest sensitive data. This social engineering method manipulates users into executing malicious payloads, bypassing traditional security controls. The malware specifically targets browser credentials, cryptocurrency wallets, and system information, posing an increasing threat to cybersecurity. The ongoing evolution of LummaStealer is evident, as cybercriminals continually refine their techniques to scale operations and evade detection.
LummaStealer, also known as LummaC2, has been active since 2022, initially appearing under the name “7.62mm Stealer” on underground forums.
Operated as a Malware-as-a-Service platform, it allows cybercriminals with varying technical skills to deploy attacks effectively. Early attacks often used malicious HTML attachments disguised as Microsoft Word files, but newer variants rely on more deceptive techniques. These updates indicate how threat actors continue to advance their operations for greater success rates and minimal detection.
One of the most concerning methods involves the FakeCAPTCHA technique, which tricks victims into executing malicious code themselves. The attack presents users with a human verification challenge, instructing them to perform seemingly innocuous actions that trigger the malware. This deceptive process starts with the user executing an mshta command, which then downloads and runs a PowerShell script disguised as an MP4 file.
The script eventually pulls the LummaC2 payload, which exfiltrates sensitive data to the attacker’s servers.
To combat this evolving threat, security professionals should monitor for suspicious PowerShell activity and unusual use of Windows utilities. Specific attention should be paid to mshta.exe interactions, clipboard data, and external network connections initiated by suspicious processes. Identifying these patterns can help detect attempts to execute the LummaStealer malware chain. As the attack techniques grow more sophisticated, staying vigilant against such deceptive methods becomes crucial for protecting sensitive information.
