Security researchers observed the LockBit ransomware leveraging brute-force techniques and evasion-based tactics to perform targeted attacks.

McAfee Labs revealed that Northwave Security was the first to spot LockBit ransomware performing such an attack. That particular incident began when a malicious actor used a brute-force method on a web server that contained an outdated virtual private network (VPN). This attempt took several days for the actor to gain the required “Administrator” password. With the key to the kingdom, the nefarious individual abused Server Message Block (SMB) to perform automated network reconnaissance to own more company systems.

In the meantime, the malicious actor had already deployed the ransomware by instructing the compromised host to run a PowerShell command that fetched a .png file from a compromised site. This host then instructed all other hosts to which the attacker gained access to execute the same PowerShell command, thereby automating the ransomware distribution process.

The payload of the retrieved dropper used two variants of a User Account Control (UAC) bypass to minimize the level of user interaction in its attack chain. It also loaded its modules dynamically to fool static analysis engines. This gave the threat the cover it needed to kill certain processes and delete shadow volume copies before it ultimately performed its encryption routine and dropped its ransom note.

Inside LockBit’s Recent Emergence

According to McAfee Labs, LockBit ransomware first emerged in 2019 with the name “.ABCD Virus.” Since then, researchers have observed a couple of instances in which the ransomware was up to no good.

For example, researchers at Sophos Labs observed at the end of April 2020 that LockBit had imitated other families such as Maze and REvil by threatening to leak non-compliant victims’ data. It was just a few days later when the Microsoft Threat Protection Intelligence Team indicated that it had witnessed LockBit using the penetration testing tool CrackMapExec to move laterally in its victims’ networks.

Defend Against LockBit Ransomware

Security professionals can help defend their organizations against ransomware like LockBit by using an endpoint management solution to monitor the behavior of their endpoints. This will help reveal malicious activity, such as an initial infection, thereby helping the organization to stop the ransomware before it spreads throughout the network. Infosec personnel should also leverage the latest threat intelligence to stay on top of the newest ransomware techniques.