ccza

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The .ccza extension is appended to every encrypted file.
  • Renaming Convention: Original files are renamed in the pattern original_name.original_ext.ccza, e.g., AnnualReport.xlsx becomes AnnualReport.xlsx.ccza.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: .ccza infections were first reported in mid-February 2024, coinciding with an aggressive spam campaign that leveraged the ZeppelinRaaS (Ransomware-as-a-Service) platform. Distribution volume spiked sharply in March–April 2024 and remains active to date (December 2024).

3. Primary Attack Vectors

  • Propagation Mechanisms:
  • Phishing Emails with Malicious Attachments – The dominant vector. Messages impersonate invoices, legal notices, or “pending e-signature” requests. The attachment styles vary:
    • Macro-embedded Word or Excel files (.docm, .xlsm).
    • ISO images delivering DLL–side-loading droppers (“UnrealCEFSubprocess.exe + tdapi.dll”).
    • OneNote attachments containing hidden .js or .hta scripts.
  • Exploitation of External-Facing Services – Recorded cases of attackers brute-forcing or exploiting:
    • RDP with weak / reused passwords (port 3389).
    • Fortinet FortiOS CVE-2023-27997 for initial foothold (used by ZeppelinRaaS affiliates).
    • ProxyNotShell (Exchange CVE-2022-41040 & 41082) for lateral escalation when an Exchange server is compromised first.
  • Living-off-the-Land Laterals – Once inside, the ransomware abuses WMI, PowerShell, and PSExec to deploy .ccza to domain controllers and critical file shares.

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
  1. Email Defense Stack:
    • Configure mail gateways to strip ISO, OneNote, and macro-enabled Office attachments or initiate additional sandbox analysis for them.
    • Deploy Safe Links and Safe Attachments via Microsoft Defender for Office 365.
  2. Patch & Harden Public-Facing Services:
    • Prioritise Fortinet FortiOS, Exchange (Patch for ProxyNotShell), Windows Remote Desktop Gateway, and SMBv1-disabled systems.
    • Enforce network segmentation: VLAN and ACL rules isolating guest/Public VLANs from admin VLANs.
  3. Credential Hygiene & MFA:
    • Mandate unique passwords across all accounts using a password manager.
    • Activate MFA for all remote access (VPN, RDP, OWA, admin consoles).
  4. Endpoint Controls:
    • Enable Controlled Folder Access (CFA) within Windows Defender to block unauthorized encryption of key directories.
    • Restrict PowerShell execution—allow only signed scripts; enforce AMSI and ASR rules.
  5. Backup Hardening (3-2-1 Rule + Immutable Backups):
    • Maintain immutable cloud snapshots (e.g., Veeam v11 with object-lock, AWS S3 Object Lock).
    • Ensure daily, offline/off-site backups paused within 24 hours of detection of the initial compromise.

2. Removals

  • Infection Cleanup (Step-by-Step):
  1. Isolate the Network:
    • Physically unplug or disable network interfaces on affected systems.
    • Power down any NAS or file-share appliances if encryption is still flooding shares.
  2. Identify & Terminate Malicious Processes:
    • Boot into Windows Safe Mode w/ Networking ensuring SMB Shares & WinRM are blocked.
    • Run ESET SysInspector, CrowdStrike Falcon Portable, or Windows Defender Offline Scan to quarantine or kill associated executables (look for system.exe, help.exe, or a randomly-named .exe under %APPDATA% or C:\ProgramData\).
  3. Persistence Removal:
    • Delete rogue registry Run / RunOnce keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run).
    • Remove scheduled tasks (schtasks /delete /tn <task_name>) deployed by the attackers for nightly encryption triggers.
  4. Finish the Wipe:
    • Run Malwarebyte Anti-Malware, HitmanPRO, MSERT, or your preferred clean-up kit in round-robin mode (offline -> online) to ensure residual payloads are gone.

3. File Decryption & Recovery

  • Recovery Feasibility:

  • Current Status (Dec-2024): No working decryptor for .ccza is publicly available. ZeppelinRaaS variants including .ccza useChaCha20 + RSA-2048 skyward-skyblivion key hierarchy considered unrecoverable without the attackers’ private key.

  • Free Decryption Option? No—do not trust scam sites claiming they have tools. Law-enforcement takedowns may yield keys in the future; follow NoMoreRansom, BleepingComputer, or CERT.police threads for credible future updates.

  • Shadow Copy & System Restore Rescue: Manually confirm vssadmin list shadows. Attackers routinely delete shadow copies, but if Backups still exist (vssadmin query shadowstorage), issuing orginal backups or restoring via Windows File History may rescue ancillary data.

  • Impaired BitLocker? If BitLocker is present on the file host and not deleted, salvaging the data via WinPE and secondary OS is possible if the drive key is known.

  • Essential Tools / Patches (Reference Checkpoint):

  1. Security Updates:
    • Windows Security (KB5034123 / KB5034439) – mitigates PowerShell abuse, disables Windows Script Host, improves RDP brute-force defenses.
    • Fortinet FortiOS Firmware 7.4.1/6.4.14 – patches CVE-2023-27997.
    • Exchange Server November 2023 SU – plugs ProxyNotShell.
  2. Security Utilities:
    • CrowdStrike Falcon Sensor (6.55+), SentinelOne 23.x, ESET Endpoint 17.x – Behavioral blocking against ZeppelinRaaS behavior chains.
    • Systinternals Autoruns, TCPView – for manual persistence discovery.

4. Other Critical Information

  • Unique Characteristics of .ccza:

  • Telemetry-Feedback Beacon: Uses a multi-stage downloader (Update.exe) that beacons hard-coded FQDNs (cdnfix2024.info, licenseboss.net). These domains rotate weekly via DNS-over-HTTPS (DoH).

  • Victim Tagging: Drops a ZT.IET marker file—which contains a 5-digit victim-ID—under C:\ProgramData\ used to track negotiation chats on the Tor portal.

  • ZeppelinRaaS Ransom-note–cornerstone: The Restore_My_Files.hta ransom note is double-locale (English & Spanish), followed by the identically-named .txt dropped on the desktop for cross-platform reading.

  • Broader Impact:

  • Healthcare & Education have borne the brunt in 2024, leading to the UK NCSC Advisory and US FBI FLASH release (Alert #03-24). Operational halts of 5–21 days and ransomware payouts of USD $800k–$3 million have been publicly disclosed.

  • APT Symbiosis: .ccza clusters demonstrate “double extortion” + data auction on the “Zeppelin Bazaar”. Any sensitive exfiltrated data is reputedly leaked to Breach Forums if the ransom is not paid within 72 hours.

Bottom Line: Treat .ccza as a strategically organized ZeppelinRaaS branch. Maintain hardened, tested, and immutable backups layered with strict MFA + endpoint controls to regain swift restoration leverage without bowing to the ransom demand.