Reverse-engineering reveals close similarities to BlackMatter ransomware, with some improvements
A postmortem analysis of multiple incidents in which attackers eventually launched the latest version of LockBit ransomware (known variously as LockBit 3.0 or ‘LockBit Black’), revealed the tooling used by at least one affiliate. Sophos’ Managed Detection and Response (MDR) team has observed both ransomware affiliates and legitimate penetration testers use the same collection of tooling over the past 3 months.
Leaked data about LockBit that showed the backend controls for the ransomware also seems to indicate that the creators have begun experimenting with the use of scripting that would allow the malware to “self-spread” using Windows Group Policy Objects (GPO) or the tool PSExec, potentially making it easier for the malware to laterally move and infect computers without the need for affiliates to know how to take advantage of these features for themselves, potentially speeding up the time it takes them to deploy the ransomware and encrypt targets.
A reverse-engineering analysis of the LockBit functionality shows that the ransomware has carried over most of its functionality from LockBit 2.0 and adopted new behaviors that make it more difficult to analyze by researchers. For instance, in some cases it now requires the affiliate to use a 32-character ‘password’ in the command line of the ransomware binary when launched, or else it won’t run, though not all the samples we looked at required the password.
We also observed that the ransomware runs with LocalServiceNetworkRestricted permissions, so it does not need full Administrator-level access to do its damage (supporting observations of the malware made by other researchers).
Most notably, we’ve observed (along with other researchers) that many LockBit 3.0 features and subroutines appear to have been lifted directly from BlackMatter ransomware.
