Lumma Stealer’s GitHub-Based Delivery Explored via Managed Detection and Response

While the tactics observed in this campaign closely align with those attributed to the threat group Stargazer Goblin, there are notable differences in execution. The infection chain begins with compromised websites that redirect to malicious GitHub release links, using URLs frequently containing the string page, suggesting a deliberate naming convention.

The compromised domains, with at least one that was built using WordPress, were exploited to host redirection mechanisms, including basic image files and PHP scripts, potentially signaling a recurring vulnerability in the group’s exploitation strategy.

The GitHub accounts used in the campaign demonstrate minimal activity and were primarily focused on creating repositories and hosting malicious releases. Both accounts exhibit highly specific behavior: creating descriptive repositories and releases, with the Readme.md content closely matching repository names. Unlike previous campaigns that relied on established GitHub accounts, these accounts show no reputation-building efforts.

The deployment of multiple malware families—including Lumma Stealer, Vidar, and SectopRAT—in a single infection reflects tactical evolution aimed at maximizing operational impact. These variations suggest deliberate adjustments by the threat actor to evade detection and enhance operational flexibility.

• Organizations can consider implementing the following examples of threat mitigation best practices to minimize or prevent malware such as Lumma Stealer from impacting their systems:
• Validate URLs and files before downloading and executing them, especially from platforms that can be used to potentially host malware like GitHub.
• Carefully inspect links and attachments in unsolicited emails, even if they appear legitimate. Hover over links to check their actual destination before clicking.
• Regularly check the validity of digital certificates for executables to ensure they haven’t been revoked.
• Use endpoint security solutions that can detect and prevent unauthorized execution of shell commands such as those used by Lumma Stealer for reconnaissance or data exfiltration.
• Identify and block communication with known malicious IP addresses and enforce strict firewall rules to mitigate C&C communication, and monitor unusual outbound traffic
• Train employees to recognize phishing emails, malicious websites, and social engineering tactics that may lead to malware infections.
• Consider partnering with an MDR provider to gain access to specialized expertise and real-time threat detection, analysis, and containment capabilities to minimize the impact of infections.
• Incorporate threat intelligence into your security posture using tools like Trend Vision One for improved detection and attribution of attacks to specific threat actors or campaigns.
• Regularly patch operating systems, browsers, and third-party applications to close vulnerabilities that could be exploited during attacks.
• Enable Multi-Factor Authentication (MFA) on all accounts. This limits the impact of stolen credentials.
• Adopt a zero-trust approach.  Implement a “never trust, always verify” philosophy for users, code, links, and third-party integrations to reduce exposure to potential threats.

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To stay ahead of evolving threats, Trend Vision One customers can access a range of Intelligence Reports and Threat Insights within Vision One. Threat Insights helps customers stay ahead of cyber threats before they happen and allows them to prepare for emerging threats by offering comprehensive information on threat actors, their malicious activities, and their techniques. By leveraging this intelligence, customers can take proactive steps to protect their environments, mitigate risks, and effectively respond to threats.

• Lumma Stealer’s GitHub-Based Delivery Explored via Managed Detection and Response

Hunting queries

Trend Vision One customers can use the Search App to match or hunt the malicious indicators mentioned in this blog post using data within their environment.   

malName:*LUMMASTEALER* AND eventName:MALWARE_DETECTION AND LogType: detection

The distribution method of Lumma Stealer continues to evolve, with the threat actor now using GitHub repositories to host malware. The Malware-as-a-Service (MaaS) model provides malicious actors with a cost-effective and accessible means to execute complex cyberattacks and achieve their malicious objectives, easing the distribution of threats such as Lumma Stealer.

The delivery of multiple threats such as SectopRAT, Vidar, and Cobeacon suggest that its perpetrators are taking a modular approach to their attacks. Future Lumma Stealer variants could include dynamically downloaded modules, enabling malicious actors to tailor payloads based on the victim’s system or industry. This could lead to more targeted attacks or even the introduction of new capabilities, such as ransomware, espionage, or cryptocurrency mining.

The campaign discussed in this blog entry aligns closely with tactics attributed to the Stargazer Goblin group, possibly indicating their involvement, despite some variations in infection chain order, URL structures, and the use of multiple payloads.

The role of Managed XDR in uncovering tactics, techniques, and procedures, as demonstrated in this recent incident investigation, highlights its critical importance for organizations. By investigating files downloaded from apparently legitimate sources like GitHub, the Managed XDR team was able to identify this threat and protect customers. This allowed the team to take swift action on affected machines to prevent further damage. Additionally, the integration of cyber threat intelligence proved invaluable, as attributing the threat to the group Star Goblin enabled the team to understand the malicious actor’s methods and anticipate other potential attacks.

Managed XDR employs expert analytics to process extensive data gathered from various Trend technologies. By using advanced AI and security analytics, it can correlate information from customer environments and global threat intelligence, producing more precise alerts and enabling faster threat detection.

Indicators of Compromise

The indicators of compromise for this entry can be found here.

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