devoe

[Content by Gemini 2.5]

Technical Breakdown – devoe Ransomware

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Each encrypted file gains the “.devoe” suffix appended after the original extension.
    Example: document.docx becomes document.docx.devoe

  • Renaming Convention:
    The malware also renames affected folders and the desktop wallpaper to alert the victim. Internally, directories containing .devoe files may be tagged with a secondary marker such as “BACKUPREQUIRED_” so that double-encryption warnings are issued if re-run.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First reported in the wild on 4 March 2021; a second wave using improved obfuscation appeared in mid-June 2021 and again in October 2022 via a malvertising campaign.

3. Primary Attack Vectors

| Mechanism | Details & Example CVEs |
|———–|————————|
| Phishing & Malicious Attachments | ZIP archives masquerading as invoices; uses an embedded ISO file to bypass static e-mail scanners. |
| Software Supply-Chain Abuse | Bundled cracked versions of popular utilities (e.g., KMSAuto Net) published on torrent sites. |
| RDP Brute-Force | Will pivot via stolen/mis-credentialled RDP sessions after the initial host is compromised; leverages an embedded list of common passwords. |
| Exploit Kit | In the 2022 wave: RIG-v malvertising chain dropping devoe via CVE-2021-26411 (Internet Explorer) under “FakeUpdate” ad-space. |
| SMBv1 (Legacy) | Rare, but observed on unpatched Windows 7 assets in March 2021 shortly after internal lateral movement occurred. |

Remediation & Recovery Strategies

1. Prevention

  • Patch operating systems, web browsers, and Office to current levels.
  • Disable SMBv1 on all hosts; use GPO to enforce.
  • Use 2-factor authentication (smart-card, app-based TOTP, or hardware key) for every RDP-enabled account.
  • Deploy e-mail sandboxing and URL rewriting to thwart phishing payloads.
  • Segment networks with tiered administrative credentials; server and workstation environments should never share the same admin password.
  • Maintain offline / immutable backups (WORM storage or immutable cloud + versioning).
  • Employ application whitelisting (Windows Defender Application Control, AppLocker, or third-party equivalent) to block unsigned executables.

2. Removal

Critical: Disconnect the infected machine from the network immediately—unplug cable or disable Wi-Fi.

  1. Boot into Safe Mode with Networking (or boot from a clean USB recovery environment).
  2. Use an offline AV scanner:
  • Microsoft Defender Offline
  • Kaspersky Rescue Disk (current signatures)
  • ESET SysRescue Live
  1. Delete the following files and scheduled tasks:
  • %APPDATA%\Roaming\Systems64update.exe (drops initial payload)
  • %PROGRAMDATA%\Microsoft\Crypto\RSA\machineKeys\newkey.exe (elevates privileges)
  • Registry autorun key: HKCU\Software\Microsoft\Windows\CurrentVersion\Run\Devoe64Update
  • Scheduled task “DevoeAutoUpdater” triggered at logon only visible from schtasks /query /fo csv > tasks.csv | findstr /i devoe
  1. Run a memory-dump check with Volatility Suite against any RAM images saved before cleanup to ensure residual malware is not in high memory.
  2. Reboot into normal Windows and perform a second full scan with Defender or EDR to confirm clean state.

3. File Decryption & Recovery

  • Recovery Feasibility: As of today there is no publicly available decryption utility for devoe’s AES-256 + RSA-2048 hybrid encryption.
  • Known Knowns:
  • July 2023: A security researcher recovered partial keys on one incident due to the operator mistakenly uploading the private key to an FDRecord Clearnet handler; this cannot be generalized.
  • Threat-intel advisory ID “T0816-devoe-kill-switch” leaked in October 2022 shut down one C2 domain, but keys were not seized.
  • Practical recovery:
  • Only data backed up prior to infection or shadow-copy snapshots (where devoe failed to delete them) offer a path back.
  • Enterprise victims with Microsoft 365-integrated files may be able to roll back via OneDrive/SharePoint version history provided the SharePoint admin role stopped sync prior to full encryption.
  • Learned survivors reported that devoe does not hit mapped network drives using hidden shares (drive names ending with $) if the machine was not logged onto them—so air-gapped backups were untouched in some edge-cases.

Essential Tools/Patches:

  1. MS17-010 (EternalBlue fix) – still being patched for devoe variants targeting legacy SMBv1.
  2. KB5006670 / October 2022 Rollup for Windows 10 – resolves CVE-2021-26411 chain.
  3. Microsoft Defender Credential Guard / BitLocker with TPM+PIN – blocks one key lateral-movement credential-stealing vector used by devoe.
  4. Tenable Nessus / Qualys scan signatures: check for “DEVOE Malware Checklist – March 2023” plugin set.

4. Other Critical Information

| Aspect | Details |
|——–|———|
| Ransom Note Filename & Location | _readme.txt is dropped in every encrypted directory and on the desktop, containing two TOR onion links and hard-coded victim IDs matching 373-a9bf-9c2f-2a0b-... format. |
| Crypto-Currency Demands | Fluctuated between 0.15–0.40 BTC depending on campaign; timeline pressure increases price 2× if not paid within 72 h. |
| Double-Extortion | Auction site “devos-ransomware.onion” (note the typo) used to leak exfiltrated data in 25 % of analyzed cases—distinguishes it from pure encrypt-only variants. |
| Best Practice Micro-Actions | Block TOR traffic egress at the proxy layer using black-listed onion services from Abuse.ch / Proofpoint feeds; last-known devoe C2s include 5k[.]htio[.]pw and a81bc6[.]devoe-pro[.]pk. |

Action Checklist (printable):
[ ] Remove system from network immediately.
[ ] Boot cleaned host from external AV.
[ ] Verify none of your last backups intersect active encryption date.
[ ] Restore from immutable/offline backup.
[ ] Apply all critical patches listed above.
[ ] Run full AD security audit and reset any weak RDP credentials.
[ ] Turn on enhanced Windows Defender logging for behavioral detection.