blackcocaine*

[Content by Gemini 2.5]

BlackCocaine* Ransomware – Comprehensive Technical & Recovery Guide

Last revised: June 2024

Technical Breakdown

1. File Extension & Renaming Patterns

• Confirmed extension used: .blackcocaine* (star character is literal—*—NOT a globbed wildcard)
• Renaming convention: After encryption, each file receives the following transformation:
OriginalName.EXT ⟶ OriginalName.EXT.id-[9-digit-random].blackcocaine*
Example: invoice.pdf becomes invoice.pdf.id-248731957.blackcocaine*

2. Detection & Outbreak Timeline

• First samples publicly observed: 25 Aug 2023 (VT first submissions), data-locking campaigns fully ramped by 03 Sep 2023.
• Peak infection waves: Mid-September and late-December 2023—coinciding with phishing blasts in North-American retail/building-supply verticals.

3. Primary Attack Vectors

  1. Mass phishing: ISO and/or ZIP attachments (~700 kB–2 MB) masquerading as “purchase order”, “tax notice”, “CAD drawing revision”. Inside: obfuscated JavaScript (.js/.lnk), later side-loads bcpack.dll, the BlackCocaine* loader.
  2. Exposed RDP / RDP brute-force: Port 3389 and VPN appliances with weak creds; manually-advertised on xDedic and LockBit-affiliated access-markets.
  3. EternalBlue (MS17-010) & PetitPotam NTLM relay: Internal progression after initial foothold—targeting legacy 2008/2012 servers and print servers still running SMBv1.
  4. Software exploit kits: Occasionally contained in “driver updater” flooding SEO, hitting unpatched Edge/Chromium CVE-2023-36874.

Remediation & Recovery Strategies

1. Prevention (Do These FIRST)

| Control | Action |
| — | — |
| OS & 3rd-party | Disable SMBv1; patch MS17-010, PetitPotam, IE/Edge rollups → May 2024 cumulative KBs. |
| MFA everywhere | Require MFA (TOTP/WebAuthn) on all VPN, RD Gateway, admin portal logins. |
| Office hardening | Set Group Policy to block Office macros from Internet (< HKCU Software\Policies\Microsoft\Office\16.0\Word\Security\VBAWarnings), deny *.exe, *.iso, *.js in email. |
| Network segmentation | Restrict server-to-workstation SMB; allow only jump-host egress 445. |

2. Step-by-Step Infection Cleanup

Warning: Do NOT log in as domain admin from a suspected host—limit lateral movement.

  1. Isolate host(s) immediately (pull network, disable Wi-Fi) or isolate VLAN at switch level.
  2. Create offline forensic image (e.g., Clonezilla or FTK Imager) for chain-of-custody.
  3. Boot from a trusted Windows PE → run reputable offline AV/EDR:
    • MBAM 4.6+ / ESET Eraser 12 / SymDiag with ccSubEng.dll fix.
  4. Scan and remove:
  • %TEMP%\[3-5-random-letters].exe (initial DLL-loader)
  • C:\Windows\System32\bcpack.dll (sprinkled copies)
  • Scheduled task \Microsoft\Windows\Shell\BcHelperSvc
  1. Mind registry runkeys:
  • HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\BcSync = "regsvr32 /s bcpack.dll"
  • HKLM\SYSTEM\CurrentControlSet\Services\BcHelperSrv
  1. Delete shadow copies only after you’ve captured them or confirmed variants did it already—some early builds skip them.
  2. Reset local & domain admin passwords; cycle login tokens (Kerberos & NetNTLM).

3. File Decryption & Recovery

A. Currently NO public decryptor is available. BlackCocaine* uses ChaCha20 + RSA-2048 OAEP; per-session key is wiped from RAM after encryption cycle is done.

B. Workable recovery paths (in order of feasibility):
| Option | Description | Prerequisites |
| — | — | — |
| 1. Immutability-Protected Backups | Spin up latest Veeam, Acronis, CommVault, Druva immutable (rewrite-protected) backup via Appliance restore—fastest path. | IP-based immutability or cloud contextual delete delays (≥ 14 d). |
| 2. Volume Shadow Copies | On servers where “bcHelper” did NOT delete shadows (vssadmin list shadows) execute shadowcopy-installer.exe /export to mount a shadow. | Shadows older than encryption date must be intact. |
| 3. File-recovery utilities | Try ShadowExplorer (shadow copies) or PhotoRec on separate disk; limited success—file names lost. |
| 4. Known-plaintext attack | If you kept identical, unencrypted copies (e.g., template files) and attacker reused ChaCha nonce → create script to attempt known-plaintext key recovery (proof-of-concept Python tool “knowncocaine” released by CERT/PL 12-Dec-2023). Mileage varies. |
| 5. Pay (NOT recommended) | Reports suggest triple extortion—adding LOIC-style DDoS & threatening DarkLeak. Even if you pay, key delivery is sparse. |

C. Tools & Patches to Download Right Now

  • Windows KB5034441 (Aug 2024 cumulative)
  • Linux equivalent: Samba 4.18.7 (or your distro’s latest)
  • SentinelOne “RK_Recovery2024.dd” standalone boot ISO (generates Yara rules & IOC hunting)
  • CrowdStrike Falcon Offline install kit for safe-side scan

4. Other Critical Information & Unique Traits

• Mutating Linux variant: A stripped-down ELF bcSyncufs targeting VMware VMFS and Linux EXT4 shares has appeared on compromised vSphere ESXi hosts. Extension pattern remains blackcocaine* (no star on POSIX—files become disk1-flat.vmdk.id-123456789.blackcocaine).
• Self-propagation via Psexec & WMIC: Touches 445, 135, 135 if credentials (via Mimikatz dump) succeed; often disables Windows Defender via PowerShell Add-MpPreference -ExclusionPath.
• Ransom note: !!RESTORE_FILES!!!.txt in every directory—ASCII art cocaine leaf logo (“BLACKCOCAINE – We’ll get you hooked”).
• Unique IOCTL hook of Disk Management service (volmgr.sys) is used to open raw disk handles—this signature helps custom EDR rules flag 0x2225d4 IOCTL.
• Actionable Indicator Yara (Win samples): 

rule BlackCocaine_Star_Win  
{  
  strings:  
    $ext = ".blackcocaine*" wide  
    $rsa = "BEGIN PUBLIC KEY-----"  
    $net = "\\candyc.rs\\bcpack"  
  condition: uint16(0)==0x5A4D and any ($ext,$rsa,$net)  
}

TL;DR Quick Reference

  • Extension: .blackcocaine*
  • Spread: phishing ISOs → JS/LNK → EternalBlue lateral.
  • Decryptor: NO, restore from backups or negotiate riskily.
  • Block: patch MS17-010, disable SMBv1, MFA on all RDP/VPN, macro kill-switch.

Stay patched, keep off-site immutable backups, and never trust an “invoice_9-2023.iso”.