Fog

MITRE ATT&CK does not currently catalogue Fog, 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: fog 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: fog persists via Registry Run Keys to ensure automatic execution after system 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: fog disables antivirus tools and modifies security software configurations to evade detection.

   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: fog deletes Volume Shadow Copies and backup directories via command-line utilities 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: fog scans network shares using native tools to identify victim hosts and expand 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.

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

   What they do: fog moves laterally through SMB/Windows Admin Shares to encrypt additional systems within the network.

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

7. T1567.002 Exfiltration to Cloud Storage Exfiltration

   What they do: fog exfiltrates stolen data via encrypted C2 channels before deploying ransomware.

   What that means: Adversaries may exfiltrate data to a cloud storage service rather than over their primary command and control channel.

8. T1486 Data Encrypted for Impact Impact

   What they do: fog encrypts victim files using custom ransomware binaries targeting critical data stores.

   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. T1490 Inhibit System Recovery Impact

   What they do: fog triggers system shutdown commands and service termination to maximize disruption and impact.

   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.

Software Fog 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.

The note this group leaves on a compromised machine. Click a filename to read it.

If you are reading this, then you have been the victim of a cyber attack. We call ourselves Fog and we take responsibility for this incident. You can check out our blog where we post company data: xbkv2qey6u3gd3qxcojynrt4h5sgrhkar6whuo74wo63hijnn677jnyd.onion You might appear there if you opt out of our communication.
We are the ones who encrypted your data and also copied some of it to our internal resource. The sooner you contact us, the sooner we can resolve this incident and get you back to work. 
To contact us you need to have Tor browser installed: 

1. Follow this link: xql562evsy7njcsngacphc2erzjfecwotdkobn3m4uxu2gtqh26newid.onion
2. Enter the code: [snip]
3. Now we can communicate safely. 

If you are decision-maker, you will get all the details when you get in touch. We are waiting for you.

If you are reading this, then you have been the victim of a cyber attack. We call ourselves Fog and we take responsibility for this incident. We are the ones who encrypted your data and also copied some of it to our internal resource. The sooner you contact us, the sooner we can resolve this incident and get you back to work. 
To contact us you need to have Tor browser installed: 

1. Follow this link: xql562evsy7njcsngacphc2erzjfecwotdkobn3m4uxu2gtqh26newid.onion
2. Enter the code: [snip]
3. Now we can communicate safely. 

If you are decision-maker, you will get all the details when you get in touch. We are waiting for you.

Ransom-note text from RansomLook, licensed CC BY 4.0.