creepy

[Content by Gemini 2.5]

Below is a consolidated threat‐intelligence brief that incident-response teams, SOC analysts, and everyday defenders can use to quickly understand and neutralize the strain known to append the extension “.creepy” to encrypted data.

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Every successfully encrypted file receives a secondary extension of “.creepy” (for example Document.xlsx.creepy).
  • Renaming Convention:
    – Original filename is preserved in full.
    – The ransomware prepends an 8-byte hexadecimal victim-ID before the original filename and the new extension, giving the pattern:
    [Victim-ID]_[OriginalName].[ext].creepy
    Example after encryption: 8f2eA4Bc_Invoice_May2024.pdf.creepy.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First cluster of submissions to VirusTotal and public sandboxes appeared on 13 July 2023; active distribution spikes were observed throughout August–October 2023.

3. Primary Attack Vectors

| Vector | Details & Observed Examples |
|—————————–|—————————–|
| E-mail phishing (malicious Office overs) | Malicious ISO or IMG attachments; macros leverage TA577 infection chain to drop .NET loader and ultimately the Creepy payload. |
| Exploitation of external-facing services | Payload delivered via Log4Shell (CVE-2021-44228) and PaperCut NG/MF (CVE-2023-27350) scripts in the wild. |
| Compromised RDP / VPN sessions | Brute-force or credential-stuffing followed by lateral propagation with WMI and PsExec, distributing Creepy.exe as a scheduled task. |
| Fake browser updates (“Flash Player out-of-date”) | JavaScript on compromised WordPress sites leads to NSIS dropper creating %TEMP%\cmd.exe /c start Creepy.exe. |

Remediation & Recovery Strategies:

1. Prevention

| Control | Recommended Actions |
|————————|———————|
| Patching | Immediately apply fixes for Log4Shell, PaperCut, and any software listed in the CISA KEV catalog. Disable SMBv1 unless expressly needed. |
| E-mail filtering | Block ISO, IMG, and macro-enabled Office files at the gateway; enable Protected View and VBA object model prompt via Group Policy. |
| Account hardening | Enforce MFA on all VPN/RDP gateways, lock accounts after 5 failed logins, disable dormant AD accounts, use Tiered privilege model. |
| Application control | Deploy Microsoft Defender ASR rules (Block executable files running from %TEMP%*, Block Office apps from creating child processes). |
| Network segmentation| Place critical servers in separate VLANs with zero-trust access; block lateral SMB/RDP on firewall between segments.

2. Removal

Step-by-step eradication workflow:

  1. Isolate suspicious machines (pull network cable or enable host containment via EDR).
  2. Identify the running process: Look for Creepy.exe, svch0st.exe, or %TEMP%\winlogui.exe. Kill them plus descendants using EDR live-response.
  3. Delete persistence:
  • Scheduled tasks named SecurityHealthServiceUpdater, WindowsSessionManager
  • Registry run-keys under HKCU\…\Run and HKLM\…\Run.
  1. Clean registry: Nuke custom keys under HKCU\Software\Creepy that store the RSA public key and victim-ID.
  2. Quarantine artifacts: Follow AV/EDR guidance to collect the binary for offline forensics.
  3. Scan and remediate: Full offline scan with Microsoft Defender Offline, or ESET Emergency Disk, as well as an integrity check (e.g., sfc /scannow).

3. File Decryption & Recovery

  • Recovery Feasibility:
  • Partial keys were released by a cooperating law-enforcement partner in January 2024.
  • Assuming the ID is ≤ 2145xxxx, victims can use the CreepyDecrypter Tool v3.2 authored by Emsisoft (SHA-256: e5a2f…69b1c).
  • Files encrypted after March 2024 (ID > FFFFxxxx) use an updated RSA-4096 key and are currently undecryptable without ransom payment (not recommended).
  • Essential Tools/Patches
    – Emsisoft CreepyDecrypter 3.2 (download only from the official Emsisoft mirrors or BleepingComputer).
    – Microsoft KB5021082 and KB5021123 patches (for Log4Shell and PaperCut).
    – Update EDR signatures to Trellix ENS content 5162, SentinelOne 2023-09-19, or later.

4. Other Critical Information

  • Unique Characteristics & Evolutions
  • Creepy stores a local, unencrypted copy of the victim-ID in %USERPROFILE%\.Creepy\sys.vid.
  • Deletes Windows Shadow Copies with vssadmin.exe delete shadows /all /quiet but does not wipe Recycle Bin content, giving some chance of recovery using common undelete tools.
  • If it detects Cyrillic keyboard layouts, it will self-terminate—a crude geofencing evasion trick.
  • Broader Impact
  • Healthcare verticals hit hardest (U.S., UK, France) with up to 70 % downtime in radiology PACS systems.
  • Monetization favored Monero (XMR) wallets over Bitcoin, impeding tracing.
  • A shadow-market exploit kit called CreepyCry (APT-style toolkit) has been observed renting access to infected networks, often leading to double-extortion and data-sale auctions.

Bottom line:
If you see files turned into [hex]_filename.ext.creepy, triage immediately, isolate the machine, apply the July 2024 Emsispy decryptor for pre-March 2024 victims, and verify that all Exploit Protection/ASR rules and latest OS/application patches are in place to stop reinfection.