drume

[Content by Gemini 2.5]

Technical Breakdown

1. File Extension & Renaming Patterns

  • Exact extension appended: .drume (lower-case)
  • Renaming convention:
    – Files keep their original names and only have .drume appended.
    – Example: Quarterly-Report.xlsx becomes Quarterly-Report.xlsx.drume
    – No e-mail address, random bytes, or victim-ID inserted in the name (this differentiates Drume from strains such as Phobos/Dharma).

2. Detection & Outbreak Timeline

  • First public submission: 02 March 2019 (Malware-Bazaar).
  • Active distribution windows: March–July 2019, with sporadic re-packaged campaigns still appearing in 2020.
  • Geographic hotspots: LATAM (Brazil, Mexico, Argentina) and South-Eastern Europe.

3. Primary Attack Vectors

  • Phishing e-mails with ISO/ZIP attachments containing malicious AutoIt or compiled NSIS droppers.
  • Exploit kits (Rig EK, Fallout EK) targeting IE & Flash Player CVEs (CVE-2018-8174, CVE-2018-15982).
  • Brute-forced RDP / Guacamole-gateway portals – the most common corporate intrusion path.
  • Software cracks & keygens posted on gaming/piracy forums (secondary vector).
  • No worm-like SMB exploit – Drume is purely a “run-once, encrypt-local” ransomware; it does not move laterally automatically, although operators manually deploy it after breaking in.

Remediation & Recovery Strategies

1. Prevention

  • Disable RDP from the Internet or place it behind a VPN with MFA; lock out accounts after 3–5 failed logins.
  • Patch OS + 3rd-party apps; apply 2019 cumulative updates that close Equation-Editor and Flash exploits.
  • E-mail: Strip ISO/IMG attachments or quarantine macros; train users to report “invoice,” “receipt,” or “shipping notification” lures.
  • Application whitelisting (WDAC/AppLocker) blocks AutoIt executables and NSIS stubs signed with invalid certs.
  • Back-ups: 3-2-1 rule – three copies, two media types, one off-line/air-gapped, verified with restore drills.
  • Deploy reputable EDR/NGAV with behaviour-based detection names “Ransom:Win32/Drume,” “Trojan-Ransom.Drume,” or “Ransom.Drume.Generic.”

2. Removal

  1. Immediately isolate the machine – pull NIC or disable Wi-Fi; do not shut down until you captured a memory image.
  2. Collect artefacts: C:\Users\<user>\AppData\Local\Temp\Au_<random>.exe, %TEMP%\NSIS*.tmp, and the ransom note +README-WHY-FILES-SO-WEIRD+.txt. Hash & upload to VirusTotal for confirmation.
  3. Terminate residual processes:
    – Au_<random>.exe, svhost.exe (misspelled), and nsis.exe.
  4. Delete persistence:
    – Registry Run keys referencing the above EXEs.
    – Scheduled task DrumeSOS (if created).
  5. Run a full scan with Malwarebytes, Kaspersky Virus Removal Tool, or Windows Defender Offline to quarantine remaining components.
  6. Patch credentials: assume the attacker harvested LSASS – force reset ALL passwords (local + domain) from a clean DC.
  7. Re-image if you have a clean gold image; otherwise continue to recovery section below.

3. File Decryption & Recovery

  • Free decryptor? NO. Drume uses Curve25519 + AES-256 in CBC mode; keys are unique per victim and uploaded to the attacker’s server.
  • Recovery options:
    – Restore from off-line back-ups (fastest, safest).
    – Windows Shadow Copies: Drume deletes them with vssadmin delete shadows /all, but check vssadmin list shadows anyway; some variants miss secondary drives.
    – File-recovery tools (Recuva, PhotoRec, R-Studio) may retrieve small files that were overwritten if disk free space hasn’t been reused.
    – Paying the ransom (0.09–0.15 BTC at the time) is discouraged – many reports of incomplete keys or lost contact after payment.
  • Data-flaw exploit: none so far; no weakness in the cryptography implementation.

4. Other Critical Information

  • Ransom note uniqueness: Markdown-styled text file with e-mail addresses [email protected] and [email protected]; demands payment within 72 h; no Tor URL.
  • No data exfiltration stage – purely encryption-only, therefore no “double-extortion” leak sites.
  • Minor coding errors: earlier builds forgot to encrypt network shares mapped with a drive letter > Z:; later builds fixed this.
  • Defensive artefacts:
    – IoC hash (dropper): 5bbf9a8fb04fe5fb6cc96762b74a0ec1a3eb15e18c725c1f3cedcedc6326f19a
    – Mutex it creates: Drume-Lock-SOS-9933
    – C2 (historic): http://185.141.63.120/ls5/panel/upload.php
  • Impact: Mostly SMBs; <2 % of 2019 global ransomware volume, but high success rate in regions with poor patching hygiene.

Share early, patch often, backup offline, and never run “cracks.” Stay safe!