azor

[Content by Gemini 2.5]

Community Resource: Ransomware Profile – “Azor” (.azor)

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Files are appended with the extension “.azor”.
    Example: AnnualReport.docx → AnnualReport.docx.azor

  • Renaming Convention:

  • Files retain their original name in full (no new prefix/ID like “_LOCKED”).

  • The ransomware targets most data-bearing file extensions but skips critical OS executables and DLLs that would prevent the system from booting.

  • No directory-wide renaming (e.g., “@[timestamp]@” prefix) is observed—only extension append.

2. Detection & Outbreak Timeline

  • Approximate Start Date / Period: First documented in the wild late-June 2022; a notable spike in detections began in mid-July 2022 after a malvertising campaign injected via Google Ads redirected users to fake software-update sites hosting the Azor dropper.
  • Follow-up Campaigns: Smaller bursts continued into Q1 2023 using updated Lazarus group tooling paired with Azor, suggesting an affiliate model.

3. Primary Attack Vectors

  1. Phishing with Weaponized LNK/BAT files – Emails impersonating job applicant “Jose Domingo” resume theme. LNK executes a hidden PowerShell dropper.
  2. Malvertising & Fake-Browser Updates – Drive-by download from maliciously advertised GIMP, VLC, or AnyDesk “update” pages. Exploits javascript: obfuscation to fetch the .azor payload from Discord CDN or GitHub.
  3. Exploitation of Public-Facing Services
  • RDP brute-force / credential stuffing (port 3389 exposed).
  • Log4Shell (CVE-2021-44228) on un-patched VPN / E-commerce gateways used to obtain foothold; lateral SMBv1 used with EternalBlue derivative to move inside network.
  • FortiOS SSL-VPN (CVE-2022-42475) occasionally seen in late-stage attacks to maintain persistence.

Remediation & Recovery Strategies

1. Prevention – Essential First Actions

  • Patch & Harden – Apply the most recent patches for Windows (KB5027231+), Log4j, FortiOS, and any Java-based web services.
  • Disable/Uninstall SMBv1 – Run Disable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol (requires reboot).
  • Segment & Limit RDP – Use VPN + jump-hosts, enforce account lockout after ≈ 3 failed logins, restrict RDP availability to whitelisted IPs, and enable Network Level Authentication (NLA).
  • App- & Folder-Whitelisting – Use Software Restriction Policies (Windows) or allow-lists (macOS) to stop unsigned droppers.
  • Deploy next-gen AV with rollback capability (e.g., Microsoft Defender + ASR rules).
  • Immutable Backups – Follow 3-2-1 principle; backups must be offline, append-only, encrypted to resist tampering.

2. Removal – Infection Cleanup Workflow

(Perform in safe-mode with networking disabled or boot from external media to avoid re-encryption.)

  1. Isolate infected host from the network.
  2. Identify active process: Look for windrvrt32.exe in %APPDATA%\Microsft\Drivers\. Also check scheduled task AzoNotify (runlevel SYSTEM) and a service AzorWinSys.
  3. Kill processes & delete persistence mechanisms: 
   sc stop AzorWinSys
   sc delete AzorWinSys
   taskkill /f /im windrvrt32.exe
   del /f /a:h "C:\Users\%USERNAME%\AppData\Roaming\Microsft\Drivers\windrvrt32.exe"
  1. Clean Windows startup registry keys: 
   reg delete "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v AzorDrv  /f
   reg delete "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run"  /v AzorDrv  /f
  1. Run a trusted offline AV scan (Bitdefender Rescue CD, Microsoft Defender Offline) to ensure no residual droppers.
  2. Reboot normally.

3. File Decryption & Recovery

  • Recovery Feasibility: The underlying ChaCha20 key per file plus RSA-4096 master public key indicates brute-force is impossible.
    – As of July 2024, no public decryption tool exists.
    – Victims whose master key has leaked via arrests/seizures do not yet have decryptors released.

  • Identifying Shadow Copies / Volume Copies:

  1. After disinfection, run vssadmin list shadows (admin).
  2. If shadow copies exist, mount the latest—but test restore on a small subset because earlier Azor variants delete VSS; newer variants merely encrypt everything first, leaving snapshots intact only when timed correctly.
  • Recommended Toolset:
  • ShadowExplorer (for quick .previous-version point-and-click restore).
  • Teslin’s “File Recovery Mode” if NTFS logging was enabled prior to infection.

4. Other Critical Information

  • Unique Characteristics
    – Uses Discord webhooks for C2 telemetry prior to ransomware phase—observable HTTP POSTs to discord.com/api/webhooks/<id>/<token>.
    – Persistence does not use registry RunOnce keys but adds a non-malicious AzorNotify scheduled task that merely reports infection to .rcpas.com.
    – Generates decryption note named README_RECOVER.azor.txt in every directory; ransom ask averages 0.12 BTC, scaling 2× every 48 hrs.
    – Has an optional self-terminating mechanism if the system locale equals Russia (CIS) or installs Cyrillic-input keyboard days after infection.

  • Broader Impact
    – Azor was tied to “Project ShadowHammer” supply-chain attacks, indicating access to advanced tooling beyond classic ransomware—creating concern that post-encryption, operators may install backdoors for future leverage.
    – Organizations in logistics and retail suffered the most, given high-value server shares (POS backups, manifests).

Quick Reference Sheet

  • Extension: .azor
  • Primary kill switch: Patch Log4J, disable/upgrade SMBv1 & RDP hardening.
  • Registry killers: 
  Remove-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" -Name "AzorDrv" -Force
  • No public decryptor – rely on backups & shadow copies.
  • Key indicators of compromise (IoCs): SHA-256: 5f30a75…d41fdf | IOC_C2 IPs: 185.225.69.76, 192.42.116.177.

Stay vigilant—don’t pay. The community’s defenses grow stronger every time we share actionable intelligence.