Helldown

MITRE ATT&CK does not currently catalogue Helldown, 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: helldown uses PowerShell scripts to execute malicious commands and spread payloads across compromised systems.

   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: helldown modifies registry run keys to establish persistence and ensure recurring 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: helldown disables security tools like antivirus software to evade detection and ensure ransomware execution proceeds unimpeded.

   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: helldown deletes Volume Shadow Copies and backup directories via command-line tools to prevent data 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: helldown dumps LSASS memory using credential-access tools to harvest user credentials for initial access or privilege escalation.

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

6. T1135 Network Share Discovery Discovery

   What they do: helldown performs network share discovery to identify accessible file shares for lateral movement and victim targeting.

   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: helldown exploits SMB/Windows Admin Shares for lateral movement between networked hosts 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: helldown encrypts victim files using strong symmetric cryptography to hold data hostage for ransom demands.

   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: helldown executes service stop commands to disable critical system services before encrypting files.

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

10. T1490 Inhibit System Recovery Impact

    What they do: helldown invokes system shutdown commands and service termination routines to disrupt recovery processes and maximize 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 Helldown 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.

--------------------------------------------------------------------------------------------
    |                                                                                          |
    |            Hello dear Management of Active directory domain                              |
    |                                                                                          |
    |            If you are reading this message,it means that:                                |
    |                                                                                          |
    |            * your network infrastructure has been compromised                            |
    |            * critical data was leaked                                                    |
    |            * files are encrypted                                                         |
    |            * backups are deleted                                                         |
    |                                                                                          |
    |            The best and only thing you can do is to cantact us                           |
    |            to setle the matter before any losses occurs                                  |
    |                                                                                          |
    |            All your critical data was leaked on our website                              |
    |            Download Tor browser:https://www.torproject.org                               |
    |                                                                                          |
    |   http://onyxcym4mjilrsptk5uo2dhesbwntuban55mvww2olk5ygqafhu3i3yd.onion                  |
    |                                                                                          |
    |            Download (https://qtox.github.io) to negotiate online                         |
    |    Tox ID:19A549A57160F384CF4E36EE1A24747ED99C623C48EA545F343296FB7092795D00875C94151E   |
    |                                                                                          |
    |                                                                                          |
    |                                                                [email protected]    |
    --------------------------------------------------------------------------------------------

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