Gootloader Unloaded

The Gootloader Initial Access-as-a-Service Operation is a growing cyber threat. It has been active since 2018 with a history of catering to top ransomware operators, one of which is the notorious REvil (Sodinokibi) gang. The Gootloader Operation and other Initial Access Brokers like it are compromising organizations across the globe and selling this access to ransomware threat actors and other cybercriminals.

Since hackers use Gootloader to get a foothold in an organization’s IT environment, Gootloader is considered a “gateway to hands-on intrusions”. Once inside the environment, threat actors spread laterally through an organization’s network to seed out ransomware or to exfiltrate data.

For the past 15 months, the Gootloader Operator has been launching ongoing cyberattacks targeting legal professionals, working for both law firms and corporate legal departments, in the U.S., Canada, the U.K., and Australia. Between January and March 2023, eSentire’s Threat Response Unit (TRU) shut down Gootloader attacks against 12 different organizations, seven of which were law firms.

Two members of eSentire's TRU, Joe Stewart, Principal Security Researcher, and Keegan Keplinger, Sr. Threat Intelligence Researcher, set about trying to come up with a way to shut down the growing Gootloader infections. Interestingly, it turned out that the Gootloader malware operator himself, has provided the answer – the operator implemented a process for hiding his payloads from being discovered by security researchers and incident responders.

Stewart and Keplinger discovered they, and other security defenders, can actually use this same feature to their advantage and proactively protect end-users. In this report, we’re sharing this method as well as Gootloader threat indicators with the cybersecurity community at large and are encouraging other security defenders to follow.

Download this report for:

• An overview of the Gootloader Initial Access-as-a-Service Operation
• An analysis of the Gootloader malware operation and the current cyberattack campaigns being launched by the Gootloader Operator
• Details showing the longtime partnership between the Gootloader Operation and the notorious REvil (Sodinokibi) ransomware operation
• Methods and threat indicators from eSentire’s TRU on how to defend your organization from the Gootloader Initial Access-as-a-Service Operation