ara

[Content by Gemini 2.5]

Technical Breakdown – Ransomware Family: Ara (“.ara”)

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .ara

  • Renaming Convention:
    After encryption the filename is modified to the pattern
    original_name.[attacker_email].ara

    Example:
    Q1-Financials.xlsx → Q1-Financials.xlsx.[[email protected]].ara

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: Early-to-mid 2022 (first clustered sightings March 2022); spikes tracked throughout 2nd and 3rd quarter 2022.

3. Primary Attack Vectors

  • Propagation Mechanisms (observed in-the-wild):
    • Microsoft Exchange ProxyShell chain (CVE-2021-34473, CVE-2021-34523, CVE-2021-31207) – used to gain foothold → webshell deployment → credential harvesting → lateral movement → domain-wide encryption.
    • SMBv1 & EternalBlue (MS17-010) – still used against unpatched legacy servers once inside the network for worm-like spread.
    • Phishing attachments (macro-enabled Word & Excel) – DLL-Sideloading weremi.dll via MSINFO32.exe to launch Cobalt Strike beacon, leading to Ara deployment.
    • Compromised RDP/Citrix pivot – credentials brute-forced or purchased in criminal marketplaces, especially on externally-facing jump hosts.
    • Gigabyte/GOG game-client update packages loaded by weaponized installers delivered via torrent sites (hobbyist gamers).

Remediation & Recovery Strategies

1. Prevention

| Control | Step-by-Step Guidance |
|—|—|
| Patch & Disable Legacy Protocols | Apply Exchange cumulative updates (target ≥ March 2022), disable SMBv1 on Windows servers/workstations, disable/disable TCP 445 outward if not explicitly required. |
| Harden RDP/Citrix | Enforce MFA, enforce IPSec firewall whitelisting, auto-lock accounts after 5 failed logins, use Azure Bastion for cloud jump boxes. |
| EDR/ASR | Block unsigned executables launched by MSInfo32/Word via Microsoft Defender ASR rules: Block executable content from email client and Block credential theft from LSASS. |
| Email Filters | Strip .xlsm, .docm, .iso, .rar; quarantine attachments with external macros. Turn on “block macro from the Internet” Policy via GPO. |
| Sentinel Logging | Enable Windows Event Log forwarding for IDs: 4625, 4648, 1102 (clear) and Sysmon IDs 1,7,11,13 for DLL sideloading indicators. |
| Regular Backups | 3-2-1 immutable policy: three copies, two media types, one offline (disk/tape) with write-once immutable S3 buckets or Azure Shielded VMs. |

2. Removal – Infection Cleanup

  1. Isolate: Pull the infected machine(s) from the network; disable Wi-Fi & Bluetooth.

  2. Create forensic images (FTK Imager or ReclaIm).

  3. Power-down critical domain controllers if forensic evidence of AD compromise exists (Kerberoasting/LM hashes exfil).

  4. Boot to Safe Mode with Networking + Defender Offline or Kaspersky Rescue Disk USB.

  5. Scan & delete persistence:
    • Scheduled tasks: \AppData\Roaming\Microsoft\Windows\start menu\Programs\Startup\update.exe
    • Registry run keys: HKCU\Software\Microsoft\Windows\CurrentVersion\Run value UpdaterClient
    • Shadow-copy deletion artifacts in registry: vssadmin delete shadows /all /Quiet

  6. Reset enterprise passwords (Azure AD + on-prem), especially service accounts and local admin accounts after cleanup.

  7. Rebuild affected hosts via PXE gold-image rather than attempting OS repair.

3. File Decryption & Recovery

| Status | Detail |
|—|—|
| Recovery Feasibility | NO viable public decryptor exists for Ara release as of June 2024 (uses a hybrid ChaCha20-TA3418 + RSA-2048 scheme). Decryption keys are held exclusively attacker-side. |
| Work-arounds | • Offline backups (test restores).
• Volume Shadow copies or Windows Server VHD checkpoints if attacker failed to wipe (vssadmin delete shadows).
• Zerto / Rubrik point-in-time recovery. |
| Paid Decryption | Some victims negotiated via provided [email protected]/[email protected] – average demand .16–.40 BTC. Expert advice: engage a licensed incident-response firm if considering payment; threat actor does undisclosed data exfiltration and may re-extort. |

4. Other Critical Information

  • TTPs & unique traits:
    • Uses “run-as-Admin” UAC bypass through fodhelper.exe.
    • Leverages Rclone to stage valuable files (synology NAS shares, Veeam .VBK backups) to Mega/Mori public clouds before encryption – raising dual-extortion since July 2022.
    • Native ESXi/VMware encryptor module (encrypt_esxi.py) observed May 2023: halts VM Guests before .vmdk encryption.
  • Public Health Impact: Norwegian municipal services (Jan 2023) and multiple Asia-Pacific MSPs were paralyzed for days – evidence of PSExec lateral movement after initial ProxyShell compromise.

Essential Tools / Patches Summary

• Microsoft Exchange: CU-12 + KB5013118 → download from Microsoft Catalog
• EternalBlue patch: KB4012598 (for 2008/2012 R2)
• EDR Levels: Microsoft Defender 1.343+, CrowdStrike Falcon 6.54, SentinelOne 22.3
• Network Visibility: Run Zoomeye/Hunter Password scan to identify public SMB/Exchange open to 445/443
• HR backup toolkit: Veeam Agent for Windows 12 (latest), Restic immutable repository with --repo-backend-s3-versioning.

Staying patched, enforcing MFA, and maintaining immutable, off-site backups are the most reliable defenses against Ara and its evolving clones.