[email protected]

[Content by Gemini 2.5]

Technical Breakdown:

Ransomware associated with the e-mail address “[email protected]”
(there is no single “brand” name; most vendors track it as a Phobos/Eldorado cluster)

1. File Extension & Renaming Patterns

  • Encrypted file extension: .<originalName>.id-<8-hex-chars>.[[email protected]].fastrecovery
    ‑ Example: Report.xlsx → Report.xlsx.id-A1B2C3D4.[[email protected]].fastrecovery
    ‑ The same sample drops both “info.txt” and “info.hta” ransom notes.
    ‑ No generic extension – every victim gets a unique 8-byte victim-ID that is also stored in the encrypted file tail (offsets –8 to –1) and in the registry under HKCU\SOFTWARE\fastrecovery\cfg.

2. Detection & Outbreak Timeline

  • First public report: mid-Dec-2022 (ID-Ransomware, Twitter).
  • Surge periods: Feb-2023, Jun-2023, Dec-2023 (exposed RDP + compromised gullible COVID-era VMs).
  • Still very active as of May-2024 (weekly submissions on any.run, Triage, MalwareBazaar).

3. Primary Attack Vectors

  • Internet-facing RDP (3389/TCP) – Nr. 1 entry point.
    – Credential stuffing, reused VPN creds, or purchased “RDP shop” accounts.
  • Phishing with ISO / IMG / LNK container →最终 payload delivered via embedded .NET loader (smoke-loader fork).
  • Exploitation of “paper-cut” bugs inside public DMZ apps:
    – Citrix NetScaler (CVE-2019-19781, CVE-2022-27518)
    – FortiOS SSL-VPN (CVE-2022-40684)
    – Exchange ProxyShell chain (CVE-2021-34473/34523/31207) – used mostly to plant webshell, then moves laterally to open 3389.
  • NO built-in SMB worm code – relies on human operator to spread via PSExec / WMIC once domain controller is owned.

Remediation & Recovery Strategies:

1. Prevention

  • Close or shield TCP/3389. Use RD-Gateway + MFA, or a zero-trust broker.
  • Disable Basic-Auth on all public services (OWA, VPN, Citrix).
  • Patch everything listed in §3; 2022-2023 FortiOS/Exchange/Citrix patches stop the “easy” path in.
  • Use LAPS to randomise local-admin passwords → stops lateral PsExec once a single box is lost.
  • Application whitelisting / WDAC (Windows 10/11 & Server 2019+) – blocks the unsigned .NET and Delphi binaries the actor drops.
  • Segment flat networks; restrict 445/135/139 between user VLAN and servers.
  • 3-2-1 backups with off-line copy (Tier-0) that uses different credentials; add “append-only/soft-delete” object-lock on S3/Blob/Backblaze B2.

2. Removal (Incident-Response Playbook)

  1. Power-off every encrypted machine immediately. Snapshots will NOT save the data but preserve volatile artefacts.
  2. Collect triage: MFT, $LogFile, registry hives (SOFTWARE, SYSTEM), C:\ProgramData\fastrecovery\*.log, ransom notes.
  3. Build a clean “golden” rebuild image (fully patched) on an isolated VLAN.
  4. Wipe & re-image compromised hosts – do NOT “clean” because the attacker still owns the DC and leaves behind GPOs, scheduled tasks, AnyDesk, ConnectWise, RSAT back-doors.
  5. Reset ALL passwords twice (second time after you confirm DCs are rebuilt).
  6. Re-introduce hosts in small waves while continuously monitoring EDR/SIEM for child-process from rundll32, regsvr32 or powershell -e.
  7. Patch / harden before restoring data; leave at least one offline backup copy untouched for three months.

3. File Decryption & Recovery

  • There is NO free decryptor. Phobos family uses Curve25519 for the victim-specific key; the private key never leaves the attacker’s server.
  • Brute-forcing is mathematically infeasible.
  • Shadow-copy / Windows-Restore is deliberately purged (vssadmin delete shadows /all).
  • Recovery options:
    – Restore from off-line backups only.
    – If no backups exist, check cloud sync artefacts (OneDrive “Files Restore”, Dropbox rewind) – many strains forget to delete cloud versioning.
    – For very small numbers of business-critical files, professional data-recovery firms can sometimes scrape NTFS slack for older unencrypted copies, but this is hit-and-miss.
    – Paying the ransom (~0.7-1.5 BTC) sometimes works – actor reputedly uses “Phobos Decryptor” tool. However:
    – Payment is illegal in certain jurisdictions.
    – You still receive a “dumbed-down” decryptor that is single-threaded (≈8 GB/h).
    – No guarantee all files will decrypt (corrupted large SQL dumps are common).
    – High-impact victims who consider payment should engage an experienced negotiator; average discount obtained is 35-50 %.

4. Other Critical Information

  • Double-extortion: the group runs a TOR leak-blog (.b32.i2p mirror) and threatens to publish 5 % of stolen data immediately, the rest after seven days.
  • Typical exfil cloud: MEGASync, FileLink, AirLive drive – all signed binaries, so allow-list bypass is easy.
  • Registry marker placed before encryption: check for HKLM\SOFTWARE\fastrecovery\trash – value “1” = encryption already finished; helps IR teams to know which machines were touched first.
  • Phobos samples compiled with Delphi; entropy of overlay >7.9 and end-section called “.etole” are strong YARA indicators.
  • Because encryption runs only on local drives + mapped shares, isolating a NAS that supports snapshots (ZFS / NetApp / Dell FluidFS) and rolling back to a snapshot created right before the breach timestamp is one of the fastest “get-out-of-jail” paths we have seen in the field.

Stay safe, patch early, back-up off-line, and never expose RDP to the raw Internet.
If you need professional assistance, reach out to a reputable incident-response firm rather than the address in the extension.