cyb

[Content by Gemini 2.5]

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension .CYB (all-caps) appended to every encrypted file.
  • Renaming Convention Plain overwrite, not a complex dual-extension format. Example:
    Budget-2024.xlsx -> Budget-2024.xlsx.CYB

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period Initial reports surfaced 10–14 August 2023 in Central-Eastern Europe. Surge observations peaked in late August and have since maintained low-moderate circulation in indiscriminate spam runs.

3. Primary Attack Vectors

  • Propagation Mechanisms
  • Phishing with DOCM lures – Malicious macro attachments launch PowerShell that fetches the CYB payload from Discord’s CDN or pastebin-like services.
  • Stolen/misused RDP credentials – Brute-force + purchase on dark-web markets; once inside, attackers run living-off-the-land scripts (certutil, powershell.exe) to stage the ransomware.
  • Exploit kits via malvertising – Rig-vEK still leveraging CVE-2022-30128 (MSHTML RCE) if Internet Explorer is present.
  • WMI/PsExec lateral movement – Internal spread once a domain controller is compromised.

Remediation & Recovery Strategies

1. Prevention (Do First)

  • Spam-filter updates: black-list macro-enabled Office documents and Discord CDN hashes used by CYB.
  • Disable Office VBA execution via GPO (vba-off, wd-disable-macro).
  • Enforce network-level authentication (NLA) on all RDP endpoints; move RDP to non-default ports + IP whitelists.
  • Segment SMB access via VLANs or host-based firewall rules (block 445 ← east-west).
  • Deploy MSHTML and Office cumulative patches from June 2023 onward (addresses CVE-2022-30128).
  • Initialize controlled folder access (Microsoft Defender ASR rule Block ransomware behaviors).
  • 3-2-1 backup strategy with one offline air-gapped copy and regular rollback tests.

2. Removal (Step-by-Step)

  1. Isolate affected machine(s) – disable NIC or pull cable.
  2. Boot to Safe Mode with Networking OFF via Windows Recovery menu.
  3. Use a clean machine to create a bootable Kaspersky Rescue Disk / Windows Defender Offline USB.
  4. Run offline AV scan to kill the parent process (%AppData%\svchostGUI.exe, random 4–6 chars) identified via Autoruns suspicious scheduled tasks.
  5. Remove persistence
  • Delete Registry run keys: HKLM\Software\Microsoft\Windows\CurrentVersion\Run\svchostGUI
  • ‑or- Autostart services named “DCompCube” or similar random 8-character service.
  1. Patch and reboot into regular mode; re-scan to confirm full eradication.

3. File Decryption & Recovery

  • Recovery Feasibility at time of writing Unsuccessful brute-forces indicate AES-256 in GCM + RSA-2048 OAEP public-key encryption; no private key implies no universal decryptor exists.

  • Essential Tools / Patches

  • Tristate backups: ESET/Acronis bare-metal images, Windows System Image, Veeam immutable Repo.

  • Incase you retained pre-infection Volume Shadow Copies, ShadowExplorer or the built-in vssadmin list shadows may recover unencrypted versions.

    DO NOT PAY – There is no guarantee the actors will restore data, and analysis shows the payment portal is now off-line.

4. Other Critical Information

  • Unique Behaviors vs. Common Ransomware Families

  • Drops a desktop wallpaper/logo referring to “CyborgProjectTeam” (pink-on-black ASCII); this is easily confused with the Cyborg ransomware from 2019 but is actually a wholly new strain.

  • Network share encryption is throttled (≤ 10 MB/s) to stay under IDS behavioral thresholds.

  • Terminates 25 mainstream AV services via WMIC (process where name="avp.exe" call terminate)—observe real-time protection restarts.

  • Creates marker file %SystemRoot%\CybReadME.html; wiping this does not prevent encryption, but its absence can be used in EDR hunting rules.

  • Broader Impact

  • Industries hit hardest: SMBs supporting education NGOs—low patch cadence plus heavy RDP exposure.

  • Attempted ransom amount: 0.35 BTC (~US$8,500 at August 2023 rates). No public reports of successful payments returned full decryption keys.

Additional Community Resources

  • Creating a simple YARA rule for .CYB files: 
  rule CYB_Ransom_Fingerprint {
      strings:
          $ext = ".CYB" ascii wide
          $logo = "CyborgProjectTeam" ascii wide nocase
      condition:
          $ext and $logo
  }
  • Feedback loop: Submit any new samples to VirusTotal (#CyB tag) and help reinforce shared block-lists.