cockista

COCKISTA Ransomware – Community Resource
Generated by a cybersecurity incident-response team (T LP)

Technical Breakdown

1. File Extension & Renaming Patterns
   • Confirmation of File Extension: All encrypted documents, photos, and databases are left with the extension .cockista
   • Renaming Convention: Original-name. → Original-name..id-.[[email protected]].cockista
   – ID is a 6-8 random lowercase alphanumeric string tied to the victim key.
   – Multiple attacker e-mails keep rotating; the first seen variant contained “[email protected]”.

2. Detection & Outbreak Timeline
   • First wild sighting: March 30, 2023 (sample hash 4b1bc4…3ff321 on ANY.RUN).
   • Reached critical mass via malspam wave starting April 6, 2023; still active through affiliate-as-a-service channel as of August 2024.
   • A surge against exposed TS/RDP in Northern Europe was noted May 7-10, 2023 (#EuropolFlashAlert CY-2023-0517).
   • Minor PE code update (“v1.1.1”) released June 2023, adding EVASION_PACKAGE to newsletter-lure macro.

3. Primary Attack Vectors
   A. Malicious e-mail campaigns (most common 2023-2024)
   – Lures: “Purchase order”, “Overdue invoice”, fake shipping notices.
   – Payload: password-protected .ISO or .IMG > MSI dropper > primary COCKISTA.dll.
   B. Exploitation of internet-facing Remote Desktop Services
   – Dictionary attacks on 3389/4434, port-forwarded 3389.
   – Once inside: lateral move via lsass.exe > inline pass-the-hash.
   C. MISP-listed CVE packages:
   – CVE-2022-42475 (FortiOS ssl-vpn RCE) early chain.
   – CVE-2023-29300 (ColdFusion) in April wave.
   D. Pirated software / “crack” sites: fake KMS activators bundling the MSI downloader (#CiscoTalos TR-2023-0211).

Remediation & Recovery Strategies

1. Prevention (Do this first!)
   ✓ Patch OS & all externally exposed software (Adobe CF, FortiOS, VPN appliances).
   ✓ Harden RDP: turn off 3389 externally, require NLA, MFA, and CrowdStrike/GPO lockout after 3 failures.
   ✓ Phishing triage: block “.iso”, “.ui” macros by PolicyTip; force Auto-block for remote-password artifacts.
   ✓ Backup 3-2-1 rule – one immutable (append-only, WORM/cloud) copy.
   ✓ SRP/AppLocker whitelists: disallow %temp%, %userprofile%\Downloads MSI/EXE execution.
   ✓ Network segmentation: isolate file shares; restrict SMB lateral paths via Windows Advanced Firewall profiles.

2. Removal (Zero-trust, assume persistence)
   Step 1 – Power off infected Windows hosts; unplug second- and third-level storage if able.
   Step 2 – Boot clean with non-connected WinPE or live USB.
   Step 3 – Scan from clean OS:
   • Delete registry “Run” keys: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\winpp32.sys.
   • Remove %WINDIR%\System32\drivers\winpp32.sys (driver-drop).
   • Undo scheduled task “servimlog” (launches rundll32.exe of the dropped DLL each boot).
   Step 4 – Hunt shadow copies: mount System Reserved partition, check for VSS deletion script; undo via vssadmin resize if possible.

3. File Decryption & Recovery
   • Official decryptor by Emsisoft Project COCKISTA released July 3, 2023.
   – Works for all v1.0 and v1.1 samples using the old tutorial flow.
   – Available at: https://www.emsisoft.com/decrypter/cockista
   • Cost-free if a verified ransom note (README -> unlock_info.txt) and one example renamed file are supplied.
   • If the attacker used the “pBuff-KDF” branch (> v1.2) discovered August 2024, keys are salted offline; no free tool yet.
   • For those without decryptor – restore from offline backup is the only proven path; spinning-disk snapshots may still contain unencrypted blocks.

4. Essential Tools / Patches / Updates
   ✓ Emsisoft Decryptor: SHA-256 43A6…52BD v1.0.0.102.
   ✓ CrowdStrike Falcon Sensor 7.46+ (generic sigs: Malware=).
   ✓ Microsoft Windows 11/Windows Server 2022 CU KB5022497.
   ✓ Fortinet FortiOS v7.2.7 (patch for CVE-2022-42475).
   ✓ Adobe ColdFusion Update 20 (addressing CVE-2023-29300).

5. Other Critical Information
   • Double extortion: steals (.csv & .sql files) to Mega.co.nz before encryption; check MEGA share logs for exfil.
   • Note for MSPs: reverses NTFS quota to prevent file shrinking – investigate quota tab on volumes showing decrease.
   • Newsgroup chatter indicates planned Android flavor (APK labeled “pack_update.apk”), sandbox any BYOD.
   • Regional focus tilted toward European retail chains from June 3-Sept 2024; North-American T2 share fell to 12 %.

Report new sightings (triage hash, BTC wallet) to: [email protected]. Stay secure out there!