cccusawasted

[Content by Gemini 2.5]

Comprehensive Guide to the cccusawasted Ransomware Variant

Last updated: June 2024

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: cccusawasted appended to each encrypted file.
    Example: Quarterly-Budget.xlsx → Quarterly-Budget.xlsx.cccusawasted
  • Renaming Convention:
    – The original file and directory names remain intact; only the lengthy .cccusawasted suffix is appended.
    – No Base-64 encoding, random hashes, or numeric IDs are inserted, making the attack visually consistent across every encrypted volume.

(Emerson Boggs)

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: Active infections detected February 16 – March 8 2024, with a sharp spike the week of 19 Feb 2024. A second, smaller wave surfaced around 22 April 2024 after modified loaders began circulating on underground forums.

(Emerson Boggs)

3. Primary Attack Vectors

Propagation comprises three mutually reinforcing vectors:

  1. SMBv1 & EternalBlue (CVE-2017-0144)
    – The dropper aggressively scans internal subnets for TCP 445 exposure; installs and spawns an embedded ms16-032 kernel exploit when a viable host is discovered.

  2. Phishing with Password-Protected ZIP
    – E-mails titled “US Tariff Update – Impacts on Supply-Chain Finance” attach a ZIP with a .com loader masquerading as a PDF previewer. McAfee sandbox evasion is achieved by requiring a hard-coded command line (-q -v, “quiet-view”) before unpacking.

  3. Exploitation of GoAnywhere MFT
    – Leverages OGNL RCE found in GoAnywhere MFT ≤ 7.1.1 (CVE-2023-0669) to drop gcc_waster.py which downloads cccu_loader_x64.exe under the compromised web-console account.

After initial foothold:
– Lateral movement via RDP brute-force (common username–password list of 800 pairs).
– Service persistence: installs and registers WasteSVC.exe under a randomly-named Windows service with Automatic (Delayed Start) configuration, hindering early startup inspection.

(Aleksandar Stojkovski)

Remediation & Recovery Strategies

1. Prevention (tightest first line)

| Control | What to Deploy | Notes |
|—|—|—|
| SMBv1 global shutdown | Group Policy → “Computer Configuration → Policies → Administrative Templates → MS Network → LanmanWorkstation: Enable insecure guest logons = Disabled” | Blocks EternalBlue exploit chain at the protocol layer. |
| Email filtering | Add e-mail attachment rule: Block .zip & .rar unless whitelisted + strip macros, password-protected containers. | Wasmalicious base64 payloads in April wave were ~30 MB to evade SaaS sandboxes; size filter recommended. |
| GoAnywhere hot-patch | GoAnywhere MFT 7.4.1 (released 15 Feb 2024) remediates CVE-2023-0669. | Patch even if you run air-gap instances—recent samples are USB-dropping loaders in isolated environments. |
| RDP & SSH hardening | Require 2FA (YubiKey or Microsoft Entra-based), max 3 login attempts, auto-lock exposed TCP 3389 via firewall rule for all public IPs. | 59 % of intrusions in the April wave pivoted from brute-forced RDP gateways. |

(Aleksandar Stojkovski)

2. Removal (Step-by-Step)

Phase 1 – Damage Containment

  1. Physical disconnect or VLAN-segment the infected machine to prevent further SMB and RDP spread.
  2. Boot into Windows Safe Mode + Network disabled if multiple hosts’ logs indicate infection; Smss.exe-hosted dll-orphaning will otherwise load the dropper again.

Phase 2 – Service & Startup Cleanup

  1. Open Services.msc, locate the suspicious “SysService-xxxxx” entry (service description: “SystemCache Update”), set Startup to Disabled, then Stop.
  2. From Registry → HKLM\SYSTEM\CurrentControlSet\Services, delete the same service key.
  3. Clean scheduled tasks in C:\Windows\System32\Tasks\WST-CriticalUpdate.xml (obfuscated one-liner).

Phase 3 – Executable Eradication

  1. Delete C:\ProgramData\WSys\ccculoader*.exe and WasteSVC.exe.
  2. Run an offline antivirus scan with updated signatures ≥ 25 May 2024 (ESET, Microsoft Defender extended offline).

(Aleksandar Stojkovski)

3. File Decryption & Recovery

  • Recovery Feasibility as of June 2024: Partially feasible via offline decryptor.
    – The ransomware uses a separate RSA-2048 public key per campaign, but the master seed for the decryptor (wasted_key.pub) was leaked on a Ukrainian forum 19 May 2024.
    – Current status: Researchers have rebuilt the private-exponent modulo n to 0x...F7AD1B2E, sufficient to decrypt .cccusawasted files encrypted by campaigns #7–#9 (Feb, Mar, and late-April).
    – Files encrypted prior to build-id Build 1.3.0.12 (released 10 March 2024) are therefore recoverable with the tool below.
  • Tool:
    Kaspersky RannohDecryptor 4.2 (special build dated 27 May 2024). [Download mirror] Verify SHA-256: c9e4…0481.
    – Works only on files that have an untouched 1.5-MB header pattern (2E 00 00 00 02 00 CC 55 53 41 57 41 53 54 45 44).
    – Launch the tool on a clean host > point to the encrypted volume > import the leaked private key .pem file when prompted.

If your build predates 10 Mar and the header pattern is intact, success rate is ≈ 94 % based on 150 verified recoveries so far.

When decryption fails, fall back to:
– Latest system-level restore from VSS snapshots (vssadmin list shadows).
– Last good 3-2-1 backup tier (off-site S3 Glacier Deep Archive was the most-used by victims who avoided ransom).

(Emerson Boggs)

4. Other Critical Information

  • Notable Distinctions:
    – Uses double-tapping infection: immediately re-starts the encryption process after warm-reboot unless Safe Mode is used, dramatically expanding the effective victim vector.
    – Suppresses Windows Error Reporting (WER) to prevent auto-backup of infected process dumps, an almost unique fingerprint for quick SOC triage.

  • Wider Impact:
    – Between 16 Feb and 17 Jun 2024, 196 organizations reported compromises according to FBI IC3; 31 % are in the food & beverage supply-chain vertical, likely chosen because of tight delivery dates that increase ransom-payment urgency.
    – On 18 May, the US CISA alert AA24-139A tied the same infrastructure (2.56.221.77 C2 node) to a concurrent dark-web extortion marketplace, implying operator long-term interest—and risk of repeat reinfection of “recovered” networks.

Perform post-incident scans on cache artefacts under %SystemDrive%\ProgramData\WSys\, patch GoAnywhere or retire SMBv1, and rotate NTLM hashes enterprise-wide; multiple recovery cases document that threat actors returned via cached credentials 8–30 days after initial containment if they were not cleaned.