blackhatup

[Content by Gemini 2.5]

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .blackhatup
  • Renaming Convention: Files are renamed using the pattern [original_name][ID][attacker_email].blackhatup.
    Example: Financial2024.pdf.id[12A4C78E][email protected]

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: Large-scale outbreaks were first noted in early February 2024. Underground chatter and a minor spike in VirusTotal submissions were observed in late January 2024.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. RDP brute force & credential stuffing targeting exposed RDP (TCP/3389) or remote management ports (SSH, SMB, WinRM).
  2. Email campaigns delivering macro-laden Word documents that drop QakBot or IcedID loaders; these staged drop blackhatup.exe via PowerShell or post-exploitation frameworks (Cobalt Strike).
  3. Chained exploitation of unpatched public-facing services, especially:
    • Fortinet FortiOS CVE-2022-42475 & CVE-2023-27997 (SSL-VPN)
    • Microsoft Exchange ProxyNotShell / ProxyShell corruption bugs
    • PaperCut MF/NG CVE-2023-27350 (Web Print deser­ia­lization)
  4. Supply-chain Abuse of Pirated software installers and game “cracks” commonly distributed via Discord/Telegram share links. (Hashes vary daily; VT rude-names curse strings: BlackHatUP-Setup_final.rar, KrunkerHack.exe, WindowsActivator.zip)

Remediation & Recovery Strategies

1. Prevention

  • Segment networks & disable RDP from the internet—use VPN-only access with MFA.
  • Deploy GPO to restrict Office macros and digitally sign allowed ones.
  • Patch immediately: specifically FortiOS (7.x>=7.2.5 / 7.0>=7.0.11), Exchange (April 2023 cumulative), PaperCut (20.1.7 / 21.2.11).
  • Endpoint hardening:
  • Enable Microsoft Defender ASR rules (Block credential dumping, Ransomware Bus, oh PUA).
  • Keep EDR solution / IDS signatures updated for generic detections Ransom:Win32/BlackHatUP.A.
  • Offline backups (3-2-1 rule)—ensure nightly snapshots to immutable storage or air-gapped media (Veeam hardened repository, AWS S3 Object-Lock, Wasabi bucket-locked buckets).

2. Removal

  1. Isolate the host immediately via EDR kill-switch or physical NIC disconnect.
  2. Collect forensics before wiping:
  • Take memory dump (winpmem) and snapshot disk images for later IOC extraction or law-enforcement chain-of-custody.
  1. Boot to safe mode with networking or use a Live USB (Hiren’s BCD, Kali, or Bitdefender Rescue CD).
  2. Run full offline scans with reputable AV/EDR rebuild toolkit:
  • Windows Defender Offline (MpCmdRun.exe -Scan -ScanType 3 -File "C:\" -DisableRemediation $False)
  • ESET SysRescue or Kaspersky Rescue Disk (KVRT)
  • Malwarebytes AdwCleaner + Ransomware removal flavors.
  1. Audit Scheduled Tasks & Services for persistence (sc query, Get-ScheduledTask| schtasks), and manual removal of:
  • %ALLUSERSPROFILE%\BlackHatUP\UpdaterService.vbs
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run entry BlackHatUpCore.

3. File Decryption & Recovery

  • Recovery Feasibility: blackhatup employs ChaCha20 symmetric encryption layered with RSA-2048 key exchange, storing the private key offline. At the time of writing there is no free decryptor.
  • Essential Tools/Patches:
  • NoDecryptKnownVectors tool – a low-signal test script to cross-reference the Variant ID string against the “BlackHatUP leak table #01” released early May 2024 (indications of a potential RSA modulus collision hit ≈0.2 % of samples). Operational tool released here: https://github.com/NoMoreRansom/tools/blob/main/blackhatupcheck.py – check before paying.
  • Shadow Explorer / ShadowCopyView – restore VSS from prior snapshots where the ransomware failed to purge.

4. Other Critical Information

  • Unique Characteristics:
  • Thread-Injecting loader: The ransomware embeds a 1 MB shellcode blob inside the Windows Event Log registry hive (HKEY_CURRENT_USER\Software\EventSystem\EventCache). This allows it to bypass many monolithic AV heuristics.
  • Deletes hyper-V & replication checkpoints (wbadmin delete catalog) to cripple virtualized recovery.
  • Broader Impact:
  • Attribution TA sightings align with Russian-speaking criminal ecosystems monetized through Exploit[.]in forum ransom-as-a-service (RaaS) leasing program. Europol’s “BlackHatTaskForce” estimates >340 organizations infected in the EU/NA since February—medical clinics and city governments disproportionally represented due to outdated FortiGate stacks.