dream

[Content by Gemini 2.5]

Technical Breakdown: Dream Ransomware

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Every file is appended with “.dream” after its original extension (e.g., report.xlsx.dream, client_backup.sql.dream).
  • Renaming Convention:
    Original → [basename].[ext].dream
    No additional random prefix, hex string, or e-mail address is pre-pended, which is a noticeable stylistic difference from many other strains.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First significant samples surfaced in late January 2024. Activity spiked in March–April 2024, coinciding with mass-phishing campaigns impersonating ISP and payroll notifications.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. Spear-phishing Attachments – Weaponized Microsoft Office documents or PDFs embedded with malicious macros or embedded objects.
  2. Remote Desktop Protocol (RDP) Brute-force – Targets exposed RDP (TCP/3389) after credential-stuffing lists. Successfully cracked accounts receive manual deployment of the payload or lateral infection via Cobalt-Strike beacon.
  3. Exploit Kits (EKs) – Early campaigns leveraged Rig EK (via Internet Explorer memory corruption CVE-2021-26411) and FakeUpdates (SocGholish) for drive-by downloads.
  4. Supply-Chain Contamination via Pirated Software – Seeders on torrent sites injected the Dream loader into cracked versions of popular utilities (Adobe, Office, CAD suites).

Remediation & Recovery Strategies

1. Prevention

  • Patch aggressively – Apply MS-Feb-2024 cumulative updates (office, IE, .NET) and disable macros from the internet via GPO.
  • Disable SMBv1 – Disable-WindowsOptionalFeature ‑online ‑featurename "SMB1Protocol" (where permitted).
  • Lock down RDP endpoints:
    • Change default 3389 to a high, non-standard port.
    • Enforce the latest RDP security layer (TLS/SSL) and NLA (network-level authentication).
  • Limit local admin proliferation. Use “Protected Users” group or LAPS for privileged accounts.
  • End-point EDR & e-mail gateway – Activate “macro execution block by origin” and “behavioral script blocking” policies in Microsoft Defender for Endpoint or equivalent engine.
  • Backups to offline media – Follow 3-2-1 rule; rotate air-gapped copies at least weekly.

2. Removal

  1. Isolate the host – pull network cable/disable Wi-Fi immediately.
  2. Boot into Safe-Mode with Networking or from Windows RE → Command Prompt.
  3. Run reputable offline AV/EDR – Sophos Bootable ISO, Microsoft Defender Offline, or Kaspersky Rescue Disk. Dream drops its loader plus a persistent registry entry: 
   HKCU\Software\Microsoft\Windows\CurrentVersion\RunOnce\
   DreamLauncher = "%TEMP%\drlaunch.exe"

Manually delete this key before rebooting.

  1. Restart into Clean OS environment and scan with full-disk EDR again.
  2. Verify lateral infection by hunting identical registry keys / filenames on adjacent systems.

3. File Decryption & Recovery

  • Recovery Feasibility: Currently NO public decryption utility exists. Dream generates a separate AES-256 key for each file, then wraps that key with a 4096-bit RSA public key embedded in the binary.
    • The private key is held exclusively on C2 and optional Tor hidden service.
    • Shadow copy deletion (vssadmin delete shadows /all /quiet) is part of the execution chain, so native Windows restore points are usually wiped.

    Mitigation tactics:
    • Check for surviving shadow copies – use ShadowExplorer or vssadmin list shadows (if backup jobs or VSS was isolated).
    • Restore from backup tape or immutable cloud snapshots (e.g., “object-lock” on S3 Compatible storage) – Dream cannot mutate those.
    • Do NOT run untrusted “decryptor” tools from forums or Telegram claims – many are themselves trojans or charge extortionate fees.

4. Other Critical Information

  • Dropper ID Strings – Sha256: 9db3a4c4…, c0ff3e7e…. Both carry the string dream_module_v2 in memory, helpful for YARA rules.
  • Ransom Note Dropped – README_FOR_DECRYPT.txt on the desktop and each root drive. Note demands ransom in XMR (Monero) to [email protected].
  • Time-Bomb Component – Files are deleted 72 hours post-encryption after executing cipher /w:C:\ to hinder forensic recovery. Clock can be rolled back if system is isolated before countdown expires.
  • Notable Differentiator – Unlike Conti/LockBit-style groups, Dream does not exfiltrate data to leak sites; actors insist they only monetize the ransomware vector, eliminating the “double-extortion” threat yet reducing victims’ leverage for demonstrating compliance.

Blockees should prioritize immutable backup validation, maintain offline tape regimens, and consider micro-segmenting critical servers from ever having direct RDP exposure.