Full Report
The following article examines forensic artifacts left by the Shade cryptolocker and maps used tactics and techniques to MITRE ATT&CK.
Analysis Summary
# Tool/Technique: Shade (Trojan-Ransom.Win32.Shade)
## Overview
Shade (also known as Troldesh) is a sophisticated ransomware family that primarily targets Windows systems. It is unique because it often functions as a multi-stage downloader that can deploy additional payloads, such as cryptocurrency miners, in addition to its primary function of encrypting user data for extortion.
## Technical Details
- **Type:** Malware family (Ransomware / Downloader)
- **Platform:** Windows (specifically targeting User mode, often found in `AppData` and `ProgramData`)
- **Capabilities:** Data encryption, persistence, defense evasion (masquerading), and delivery of secondary payloads (cryptominers).
- **First Seen:** Approximately 2014 (The analyzed version shows active campaigns through 2019-2020).
## MITRE ATT&CK Mapping
- **[TA0001 - Initial Access]**
- [T1566.001 - Spearphishing Attachment]
- **[TA0002 - Execution]**
- [T1204.002 - User Execution: Malicious File]
- [T1059 - Command and Scripting Interpreter]
- **[TA0003 - Persistence]**
- [T1547.001 - Registry Run Keys / Startup Folder]
- **[TA0005 - Defense Evasion]**
- [T1036 - Masquerading (e.g., EXE files renamed to .JPG)]
- **[TA0040 - Impact]**
- [T1486 - Data Encrypted for Impact]
- [T1496 - Resource Hijacking]
## Functionality
### Core Capabilities
- **Weaponized Scripts:** Utilizes JavaScript (.JS) files contained within email archives to initiate the download chain.
- **Data Encryption:** Encrypts user files, typically appending the `.CRYPTED000007` extension.
- **Ransom Communication:** Generates "README" files and modifies the desktop wallpaper to provide decryption instructions.
- **Persistence:** Establishes itself in the Windows Registry `Run` keys to ensure it remains active after a reboot.
### Advanced Features
- **Multi-Payload Delivery:** Beyond ransomware, Shade is known to install ZCash miners (e.g., using `NHEQMI~1.EXE`).
- **Stealthy Execution:** Uses VBScripts (`.vbs`) to wrap and launch command-line tools silently in the background, hiding console windows from the user.
## Indicators of Compromise
- **File Names:**
- `README.txt` (or similar ransom notes)
- `leWRX7w.cmd` (Persistence script)
- `pxNXSB.vbs` (Temporary script for hidden execution)
- **File Extensions:** `.CRYPTED000007`
- **Registry Keys:** `HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run` (containing paths to random-named executables in Roaming folders).
- **Network Indicators:**
- `eu1-zcash.flypool[.]org:3333` (Mining pool connection)
- **Behavioral Indicators:**
- `wscript.exe` launching hidden `.cmd` files.
- Unexpected creation of `.vbs` files in the `%TEMP%` directory.
- High CPU utilization due to the associated miner payload.
## Associated Threat Actors
- Generally attributed to cybercriminals operating under the "Shade" or "Troldesh" moniker; historically associated with Russian-speaking threat actors.
## Detection Methods
- **Signature-based:** Monitoring for the specific naming convention of the encrypted file extensions and the hash of the JavaScript downloaders.
- **Behavioral Detection:** Monitoring for the `WScript.Shell` execution of files located in `C:\ProgramData` or `AppData`, and detecting unauthorized encryption patterns (rapid file renaming/modification).
- **Forensic Artifacts:** Searching for `.cmd` and `.vbs` files in `ProgramData` that contain mining pool configurations or hidden execution scripts.
## Mitigation Strategies
- **Email Security:** Implement robust attachment filtering to block or sandboxing `.JS`, `.WSF`, and `.ZIP` files from unknown external senders.
- **User Education:** Train employees not to execute scripts or macros from unsolicited emails.
- **Backup Policy:** Maintain offline, immutable backups to recover from encryption without paying the ransom.
- **Endpoint Hardening:** Restrict the execution of scripts (Windows Script Host) if they are not required for business operations.
## Related Tools/Techniques
- **ZCash Miner (nheqminer):** Often bundled as a secondary payload for financial gain.
- **Masquerading:** The technique of downloading `.exe` files disguised as `.jpg` images to bypass basic web filters.