Bluesky

MITRE ATT&CK does not currently catalogue Bluesky, 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: bluesky executes PowerShell scripts to stage payloads and manipulate system processes.

   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: bluesky 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: bluesky disables antivirus 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.

4. T1027.013 Encrypted/Encoded File Stealth

   What they do: bluesky encodes victim data with symmetric encryption keys before demanding ransom payments.

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

5. T1070.004 File Deletion Stealth

   What they do: bluesky deletes Volume Shadow Copies and backup directories via vssadmin and file deletion commands.

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

6. T1018 Remote System Discovery Discovery

   What they do: bluesky performs remote system discovery to map network topology and locate high-value targets.

   What that means: Adversaries may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for Lateral Movement from the current system.

7. T1135 Network Share Discovery Discovery

   What they do: bluesky scans network shares using SMB tools to identify victim systems 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.

8. T1486 Data Encrypted for Impact Impact

   What they do: bluesky encrypts victim files using custom ransomware binaries 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.

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

<<< B L U E S K Y >>>

YOUR IMPORTANT FILES, DOCUMENTS, PHOTOS, VIDEOS, DATABASES HAVE BEEN ENCRYPTED!

The only way to decrypt and restore your files is with our private key and program.
Any attempts to restore your files manually will damage your files.

To restore your files follow these instructions:
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1. Download and install "Tor Browser" from https://torproject.org/

2. Run "Tor Browser"

3. In the tor browser open website:
   http://ccpyeuptrlatb2piua4ukhnhi7lrxgerrcrj4p2b5uhbzqm2xgdjaqid.onion

4. On the website enter your recovery id:

RECOVERY ID: [snip]

5. Follow the instructions


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