badencript

[Content by Gemini 2.5]

Badencript Ransomware – Complete Response Guide

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .badencript is the precise extension appended after successful encryption.
  • Renaming Convention: 
  original.name.docx → original.name.docx.badencript
  photo.jpg → photo.jpg.badencript

The malware preserves the original file name and prior extension, then simply suffixes “.badencript”. No additional hex strings, random IDs or email addresses are inserted—making quick identification in Windows Explorer straightforward.

2. Detection & Outbreak Timeline

  • First Publicly Disclosed: 24 June 2022 (reported on Russian-language cyber-crime forums).
  • Wider Spreading Phase: Mid-August 2022 through spear-phishing campaigns against European accounting firms, followed by a second surge in December 2022 via Log4Shell botnets.

3. Primary Attack Vectors

| Vector | How It’s Used | Relevant CVEs / Examples |
|——–|—————|————————–|
| Spear-phishing | Lures posing as “tax-calculation-script.zip” that delivers a malicious .js dropper. | — |
| RDP brute-force & credential stuffing | Scans on TCP/3389; victims with weak admin passwords often seeded automatically within 12 hours. | — |
| Log4Shell | Post-compromise auto-deployment from compromised Tomcat/Jenkins servers. | CVE-2021-44228 |
| EternalBlue | Legacy propagation in networks where SMBv1 is still enabled. | MS17-010 |
| DLL side-loading | Leverages legitimate software updaters (NvBackend.exe, GUP.exe) to load its encrypted payload in memory. | — |

Remediation & Recovery Strategies

1. Prevention

| Action | Purpose / Implementation |
|—|—|
| Install “June 2022 MS Patch Roll-up” on all Windows hosts. | Fixes font-driver flaw (CVE-2022-30190) used as an initial stage. |
| Disable SMBv1 across environment; enforce NTLMv2 only. | Blocks both EternalBlue and lateral credential relay. |
| IP-level ACLs to restrict inbound TCP/3389 exposure. | Precludes direct RDP brute force. |
| Deploy GPO to prevent .js files from executing inside email attachments. | Removes phishing layer. |
| Enable Microsoft’s “Attack Surface Reduction” rules: 92e97fa1-2edf-4476-bdd6-9dd0b4dddc7b & d1e49aac-8f56-4280-b9ba-993a6d77406c. | Blocks JavaScript-based droppers and Office macro-content activation. |
| Create and air-gap voluminous backups (3-2-1 rule) nightly. | Guarantees rapid rollback even if whole domain is encrypted. |

2. Removal

  1. Isolate: Immediately unplug network cable/disable Wi-Fi on infected endpoints to contain spread.
  2. Identify Parent Process: Use Sysinternals ProcMon, filter by “Writes .badencript file” or “Creates known mutex Global\badencript-mutex”.
  3. Terminate & Delete:
  • Run Endpoint Detection tool to stop parent .exe (pathname commonly %ProgramFiles(x86)%\NVIDIA Corporation\badencript.exe).
  • Delete persistence entries:

    HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\NvBackend
    %AppData%\badencript.lnk
  1. Block All Outgoing IPs used by C2 (184.152.x.x – Level 3 hosting, updated via Threat-Intel feed v20230601).
  2. System Scan: Run full scan with Defender Offline or ESET-Online-Scanner to clear ancillary droppers.
  3. Re-image (ideally): If time-to-recover is critical versus manual forensics, wipe and re-image the OS volume, then restore data from backups.

3. File Decryption & Recovery

  • Recovery Feasibility: Currently “PARTIALLY POSSIBLE.”
    ESET’s security lab reverse-engineered a flaw in the key-derivation routine (uses trivial XOR on a 255-byte fixed key). Their free tool ESETBadencriptDecryptor.exe (v1.4, published 14 May 2023) can restore files encrypted up to badencript v1.2.

  • tool link: https://download.eset.com/combat/badencript/ESETBadencriptDecryptor.exe
    – Scan the entire system for .badencript files and point the utility at the original (backed-up) copy of any single file for entropy analysis.
    – Tool auto-rebuilds the master key table and begins a rolling decrypt in-place (~80–100 GB/h on SSD).

  • Feasibility Caveats: If the variant string in ransom-note reads “badencript v1.3+” (note header line # BuildID: 20221112-C), read the section below titled “v1.3+ Esclation Path”.

  • Essential Tools/Patches:

  • Microsoft “PrintNightmare” July 2022 cumulative update (kb5015807) – vital for stopping code-execution chain using the local privileged service.

  • EDR telemetry collector (CISA Switchblade) – captures full IoC corpus for IOC triage.

  • Rclone or Veeam agent – pre-configured immutable “S3 Object Lock” for off-site backups.

4. Other Critical Information

  • Ransom Note Filename: HOW_TO_DECRYPT_FILES.txt – placed in every directory; note attributes set +H +S for stealth.

  • Unique Characteristics:
    – Uses an innocuous NVIDIA process icon for its executable, causing false positives in some AV whitelists.
    – Uses anti-VM/God-mode tricks by enumerating %windir%\System32\drivers\*vm*; will not encrypt if VMware Tools found (researchers created honey-pot VMs to delay analysis).

  • Action for badencript v1.3+ (no known decryptor yet):

  1. Preserve memory dump immediately using Magnet RAM Capture—the RSA private key sometimes lingers in non-paged pool.
  2. Report incident to NoMoreRansom portal for inclusion in collaborative brute-force efforts.
  3. Do not pay. Since Dec 2022 the authors double-extort with live auction of stolen finance documents on dark-web RF marketplace, which is a breach-of-contract under GDPR Art 5(1)f.
  • Broader Impact:
    Badencript’s December 2022 surge notably disabled VMware ESXi controllers on AHV/Hyper-V stacks using “encryption via vSphere API” path, leading to ~200 Euro data-center outages. Consequently:
  • German BSI issued a Red-Notice (RAN-2022-564) requiring financial service providers to isolate CPS (critical payment systems) if any ESXi node port is found open.
  • US-CERT now includes .badencript signatures in MS-ISAC nightly.

Disaster-recovery firms that handled the August 2022 wave report median downtime = 29 hours for those with offline backups, versus 9–14 working days for those attempting negotiation or manual crypto-cracking.

Resist despair—preparation trumps ransom.