24th April 2021, Kathmandu
Mount Locker group first announced their ransomware-as-a-service offering in the second half of 2020, and attacks attributed to the variant have been on the rise since. In early November 2020, an update was released broadening the types of files targeted and improving the ransomware’s ability to evade security measures. It also appears that Mount Locker may be transitioning to Astro Locker, as the verbiage and victims listed on both variants’ shaming sites share significant overlap. While it’s not too uncommon for malware to change names, this change is paired with an aggressive shift in Mount Locker’s tactics.
Traditionally, Mount Locker ransomware is known for using public tools to move laterally, steal files, and deploy encryption. Attackers deploying Mount Locker use its capabilities for double extortion of victims. Initial access vectors vary, but once a foothold is gained common tactics include the use of AdFind and Bloodhound for Active Directory and user reconnaissance, FTP for file exfiltration, and CobaltStrike for lateral movement and the delivery and execution of encryption, potentially through psExec. Critical data is staged and exfiltrated to be used as further collateral in extorting ransoms, with threats to release the data if the ransom is not paid.
