Osiris

MITRE ATT&CK does not currently catalogue Osiris, 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: osiris executes PowerShell scripts to stage payloads and manipulate system processes during initial compromise.

   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: osiris adds malicious registry run keys to ensure persistence across reboots.

   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: osiris 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. T1685.005 Clear Windows Event Logs Defense Impairment

   What they do: osiris clears Windows Event Logs using PowerShell to erase forensic evidence of intrusion.

   What that means: Adversaries may clear Windows Event Logs to hide the activity of an intrusion.

5. T1070.004 File Deletion Stealth

   What they do: osiris deletes Volume Shadow Copies via vssadmin /delete shadows to prevent recovery.

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

6. T1135 Network Share Discovery Discovery

   What they do: osiris scans network shares using net use commands to map accessible directories for lateral movement.

   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.

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

   What they do: osiris exploits SMB shares to propagate payloads across networked systems within victim environments.

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

8. T1486 Data Encrypted for Impact Impact

   What they do: osiris encrypts victim files using a custom ransomware algorithm targeting documents and backups.

   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.

9. T1489 Service Stop Impact

   What they do: osiris executes kill.bat commands to stop critical services and disrupt operational systems.

   What that means: Adversaries may stop or disable services on a system to render those services unavailable to legitimate users.