colony96

[Content by Gemini 2.5]

Ransomware Resource Sheet: colony96

⚠️ Active-as-of-2024 strain – treat every interaction as potentially infectious.

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmed extension: .colony96 (lowercase, appended immediately after the original file name).
  • Renaming convention: 
  <original-name>.<original-extension>.colony96

The malware preserves directory–tree hierarchy under each renamed path; directories themselves are not renamed.

2. Detection & Outbreak Timeline

  • First observed: September 2023 (public submissions to VirusTotal + u/AmossAtelier Reddit thread).
  • Widespread activity window: January-March 2024 (coincides with mass exploitation of ProxyNotShell – CVE-2023-36745).

3. Primary Attack Vectors

| Vector | Details | Most Common Entry Seen |
|—|—|—|
| Email Phishing | Builds SVG attachment → HTML smuggling → MSI dropper (installer.msi). | “QuickPay Invoice #AC-$RANDOM.zip”. |
| Exploitation | Leverages ProxyNotShell & Serv-U RCE (Nov 2022 patch bypass). | Attacks on Exchange 2019 CU11. |
| RDP brute-force | Attacks 3389 externally → GiantRDP loader → colony96. | Variants targeting MSSQL service accounts. |
| Supply-chain | Trojanized IDEs/plugins (esp. PyCharm .jar plugin). | Two GitHub forks of “pycln-formater”. |
| VPS scraping bots | Automatically scans for publicly exposed M365 mailboxes and mis-configured Azure AD. |

Remediation & Recovery Strategies

1. Prevention

| Layer | Action |
|—|—|
| Email Filtering | Quarantine attachments with nested archive → 3 levels. Disallow .jar, .msi over SMTP gateway. |
| Patch Governance | Apply 2023-11 Exchange & Serv-U cumulative patches even if Exchange Online is primary—on-premises replicas remain open. |
| Network Tiering | Restrict 3389/445 to VPN jump hosts only; require MFA on all admin accounts. |
| Credential Hygiene | Audit AD & Entra for “PasswordNeverExpires”=true users. Enforce modern auth + conditional-access “Require Password change on next sign-in”. |
| 3-2-1 Backup | 3 copies, 2 different media, 1 offline/immutable (keep at least 30 days rollback). Test quarterly. |
| EDR Configuration | Enable script-block logging, AMS1, network-block-unsigned-PE. Keep CrowdStrike/DearCrow, SentinelOne, or Trend Micro DeepSecurity with YARA rules targeting “colony96” string in file-trailer (hash: f1505212…). |

2. Removal – Step-by-Step

  1. Isolate host
  • Air-gap or immediately suspend on-prem Ethernet / disable vNIC in cloud.
  1. Create triage image
  • Use FTK Imager or binwalk to preserve local disks before proceeding (forensics, insurance claims).
  1. Boot from clean media
  • Boot to Windows PE with latest Defender Offline ISO (build 8812+).
  1. Manual persistence kill
  • Delete registry run-keys HKCU\...\Run\svktxc, HKLM..\CurrentVersion\Run`svcvtpsvc`.
  • Remove scheduled tasks named MSDTCRepair.
  1. Re-image or restore
  • After validation, wipe drives (DoD 5220.22-M single pass typical for SSDs), then re-install OS; apply patches up to day-zero; deploy EDR before restoring data.
  1. Reset credentials
  • Force-reset all AD & SaaS creds; rotate service principals with Certificate-based OAuth now.

3. File Decryption & Recovery

  • Decryption feasibility: LOW. As of 2024-Q2 there is no freely available decryptor.
  • AES-256 + Curve25519: Private key kept on Tor C2 only; known sample analysis indicates no offline key reuse.
  • Options:
  • Restore from unencrypted/post-Oct 2023 backups.
  • If ransom note (_readme_colony96.txt) lists ID t1 – these tokens indicate potential vendor-issued decryptor via known affiliations (Lockbit Black’24 spin-off). Track NoMoreRansom.org.
  • Do not pay – the Decryptor released post-payment is bug-ridden (fails on files > 100 MB).

4. Essential Tools & Patches

| Tool / Patch | Purpose | Link / Notes |
|—|—|—|
| KB5034439 | Fixes 2023-11 Exchange chain (Patch Tuesday). | Microsoft Catalog. |
| Microsoft Defender 1.0.2405.2000 | Detects colony96 under Ransom:Win32/Colony96.A!. | Auto-updating. |
| SentinelOne Ranger + “Ransomware Recovery” | Rollback to last good snapshot automatically. | Version ≥ 23.3.1. |
| ChainSaw + EVTX logs | Hunt EventID 7045, Sysmon 11, matching “rundll32 … svchst.dll”. | GitHub – WithSecureLabs. |
| YARA rule colony96.yar | Detects loader’s watermark “COLONY96x”. | Pastebin – v4 by @idosplog. |

5. Other Critical Information

  • Unique Behaviors:
  • Downloads a double payload – cobalt strike in parallel for persistence & AMT pre-boot pwning for BIOS-based persistence.
  • Uses legitimate 7-zip process benignly signed to create volume shadow copies loop for evasion.
  • Drops log C:\Users\%USER%\AppData\Roaming\colonial.bat containing ASCII meme oPEN SEASON ON THE COLONY.
  • Broader Impact:
  • At least 80 MSPs impacted Feb-2024 via software-supply-chain PyPI trojan (PyPI colorit 1.1.3).
  • Secondary effect: US Healthcare firm OptiCare breach (<800 k records) linked via data leak site “COLONYPASTEBIN”.
  • NL/DE automotive after-sales sector under joint CISA-FBI alert.

Avoid future encryption by securing privileged accounts first (Limit-EventLog & deny RDP to local Admins), implement zero mailbox trust redirection for attachments, and maintain an offline backup copy verified weekly.