Obscura

MITRE ATT&CK does not currently catalogue Obscura, 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: obscura executes malicious commands via PowerShell scripts to stage payloads and manipulate system behavior.

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

2. T1685 Disable or Modify Tools Defense Impairment

   What they do: obscura disables antivirus and monitoring tools by terminating security processes and modifying system 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.

3. T1027.013 Encrypted/Encoded File Stealth

   What they do: obscura encodes victim files with custom symmetric encryption routines before demanding payment.

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

4. T1070.004 File Deletion Stealth

   What they do: obscura 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. T1003.001 LSASS Memory Credential Access

   What they do: obscura accesses and dumps LSASS memory to steal credentials for lateral movement and persistence.

   What that means: Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).

6. T1049 System Network Connections Discovery Discovery

   What they do: obscura enumerates network connections and service ports to identify high-value targets for 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.

7. T1135 Network Share Discovery Discovery

   What they do: obscura scans network shares using native tools to identify victim file structures and encryption targets.

   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.

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

   What they do: obscura moves laterally through SMB/Windows Admin Shares to compromise additional networked systems.

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

9. T1486 Data Encrypted for Impact Impact

   What they do: obscura encrypts victim files using custom ransomware binaries targeting critical business and personal data.

   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.

10. T1490 Inhibit System Recovery Impact

    What they do: obscura halts system recovery processes by stopping critical services and disrupting backup restoration mechanisms.

    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.

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

Good day! Your company has failed a simple penetration test.

>> Your network has been completely encrypted by our software.

Our ransomware virus uses advanced cryptography technology that will make it very difficult for you to recover your information.

>> All information has been stolen.
We have stolen all information from all devices on your network, including NAS. The data includes but is not limited to: employee passport details, internal documentation, financial documents, and so on.

>> You have about 240 hours to respond.
If there is no response, all stolen information will be distributed.
We are waiting for you to decide to write to us, and we will be happy to negotiate a ransom price with you. By paying the ransom, you will also receive:
1) a report on how we infiltrated your network
2) instructions + software that decrypts all files
3) our assistance in recovery, if needed.

>> They will not help you; they are your enemies.
Recovery agencies, the police, and other services will NOT HELP you. Agencies want your money, but they do not know how to negotiate. 

If you think you can restore your infrastructure from external backups that we did not access, we warn you:
1) The laws of any country impose huge fines on companies for information leaks.
2) Playing against us will not work in your favor. We will gladly wipe every one of your servers and computers.

When you write to us, we expect to hear from you who you are and what your relationship to the company is.
Your ID: [snip]
TOX: AE55FC0EB1C25A5B081650108F9081E236DECE1CE08D2E185A6F15B9FB48E700210BED374643
Blog: http://obscurad3aphckihv7wptdxvdnl5emma6t3vikcf3c5oiiqndq6y6xad.onion/
Obscura. 2025.

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