Mount-locker

MITRE ATT&CK does not currently catalogue Mount-locker, so this is our assessment of the techniques it uses, drawn from public reporting. The techniques themselves, and every "what that means" definition below, come from MITRE ATT&CK v19.2. Confidence: medium. Treat it as orientation, not attribution.

1. T1059.001 PowerShell Execution

   What they do: mount-locker executes PowerShell scripts to deliver ransomware payloads and manipulate system processes.

   What that means: Adversaries may abuse PowerShell commands and scripts for execution.

2. T1547.001 Registry Run Keys / Startup Folder PersistencePrivilege Escalation

   What they do: mount-locker adds malicious registry run keys to ensure ransomware execution upon system reboot.

   What that means: Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key.

3. T1685 Disable or Modify Tools Defense Impairment

   What they do: mount-locker disables antivirus tools by terminating security processes and modifying Windows Defender settings.

   What that means: Adversaries may disable, degrade, or tamper with security tools or applications (e.g., endpoint detection and response (EDR) tools, intrusion detection systems (IDS), antivirus, logging agents, sensors, etc.) to impair or reduce visibility of defensive capabilities.

4. T1027.013 Encrypted/Encoded File Stealth

   What they do: mount-locker encodes ransom notes and configuration files using custom XOR encryption to evade detection.

   What that means: Adversaries may encrypt or encode files to obfuscate strings, bytes, and other specific patterns to impede detection.

5. T1070.004 File Deletion Stealth

   What they do: mount-locker deletes Volume Shadow Copies and backup directories via vssadmin commands to prevent recovery.

   What that means: Adversaries may delete files left behind by the actions of their intrusion activity.

6. T1018 Remote System Discovery Discovery

   What they do: mount-locker performs remote system discovery via SMB ports to map the victim network for lateral movement.

   What that means: Adversaries may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for Lateral Movement from the current system.

7. T1049 System Network Connections Discovery Discovery

   What they do: mount-locker enumerates active network connections to identify compromised hosts for targeted encryption.

   What that means: Adversaries may attempt to get a listing of network connections to or from the compromised system they are currently accessing or from remote systems by querying for information over the network.

8. T1135 Network Share Discovery Discovery

   What they do: mount-locker scans network shares using net use commands to identify victim files for encryption.

   What that means: Adversaries may look for folders and drives shared on remote systems as a means of identifying sources of information to gather as a precursor for Collection and to identify potential systems of interest for Lateral Movement.

9. T1021.002 SMB/Windows Admin Shares Lateral Movement

   What they do: mount-locker uses SMB/Windows Admin Shares to propagate ransomware binaries across networked machines.

   What that means: Adversaries may use Valid Accounts to interact with a remote network share using Server Message Block (SMB).

10. T1486 Data Encrypted for Impact Impact

    What they do: mount-locker encrypts victim documents and system files using strong symmetric encryption algorithms.

    What that means: Adversaries may encrypt data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources.

Software Mount-locker has been seen using, grouped by what it is used for. Legitimate administration tools appear here because these actors routinely abuse them — presence in this list is not itself malicious.

Tool data from Ransomware Tool Matrix by BushidoUK, licensed CC BY 4.0. Grouped by purpose and matched to this group by Breach House.