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Summary
In January, Netskope Threat Labs observed a new malware campaign using fake CAPTCHAs to deliver Lumma Stealer. Lumma is a malware that works in the malware-as-a-service (MaaS) model and has existed since at least 2022. The campaign is global, with Netskope Threat Labs tracking victims targeted in Argentina, Colombia, the United States, the Philippines, and other countries around the world. The campaign also spans multiple industries, including healthcare, banking, and marketing, with the telecom industry having the highest number of organizations targeted.
Researchers have observed attackers delivering Lumma via multiple methods, including cracked software, the Discord CDN, and fake CAPTCHA pages. The payloads and techniques involved in the infection chain also vary, with the attackers employing techniques like process hollowing and PowerShell one-liners. In this recent campaign, Netskope identified new payloads being delivered, new websites employing malvertising, and the use of open source snippets to bypass security controls.
Key findings
- A new Lumma Stealer campaign using fake CAPTCHAs, multiple new websites employing malvertising, and multiple new payloads and evasion techniques targeting Windows users worldwide.
- The infection chain includes a step where the attacker asks the victim to execute a command from their clipboard using the Windows Run command, making it difficult to flag via technologies like browser-based defenses.
- One of the payloads contains a snippet based on an open-source tool for bypassing Windows Antimalware Scan Interface (AMSI), a step designed to evade malware protection capabilities.
Details
The infection chain typically begins when the victim visits a website that redirects them to a fake CAPTCHA page. Once the victim accesses the URL, a fake CAPTCHA is displayed,