Crylock

MITRE ATT&CK does not currently catalogue Crylock, 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. T1078.002 Domain Accounts Initial AccessPersistencePrivilege EscalationStealth

   What they do: crylock leverages domain accounts harvested via credential dumping to access networked systems.

   What that means: Adversaries may obtain and abuse credentials of a domain account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.

2. T1059.001 PowerShell Execution

   What they do: crylock executes PowerShell scripts to stage payloads and manipulate system processes.

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

3. T1685 Disable or Modify Tools Defense Impairment

   What they do: crylock disables antivirus tools by terminating security processes and modifying service configurations.

   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. T1070.004 File Deletion Stealth

   What they do: crylock deletes Volume Shadow Copy and backup files using vssadmin commands to prevent recovery.

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

5. T1135 Network Share Discovery Discovery

   What they do: crylock 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.

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

   What they do: crylock moves laterally through SMB shares to encrypt additional servers across the network.

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

7. T1486 Data Encrypted for Impact Impact

   What they do: crylock encrypts victim files using custom ransomware binaries targeting documents and images.

   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.

8. T1490 Inhibit System Recovery Impact

   What they do: crylock calls system recovery inhibitors like shutdown scripts to maximize operational disruption.

   What that means: Adversaries may delete or remove built-in data and turn off services designed to aid in the recovery of a corrupted system to prevent recovery.