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Trojan:VBS/Turla
Aliases: No associated aliases
Summary
Trojan:VBS/Turla covers a family of VBScript-based tools used by a sophisticated threat actor for initial reconnaissance and system profiling. These tools rely on VBScript components that run inside native Windows interpreters such as Windows Script Host (wscript.exe), the command shell (cmd.exe), and the HTML Application host (mshta.exe). By using built-in Windows features, the scripts avoid dropping custom binaries that security products often flag. The KopiLuwak framework, first observed in 2016, is a primary example of this scripting architecture. It acts as a bridge between an initial infection and later deployment of persistent backdoors.
The threat actor delivers these scripts through several methods, including spear phishing with malicious Office documents, watering hole attacks on compromised legitimate websites, and re-registering expired domains from older malware campaigns. Once launched, the VBScript performed an extensive survey of the compromised machine and its network environment. It encrypts the collected data and sends it to a command-and-control (C2) server. The C2 server can then issue commands, download additional payloads, or instruct the script to remove itself. Persistence is achieved through registry modifications that trigger the script at user logon or system startup.
- Immediately disconnect the affected device from the network. For virtual machines, use network isolation without powering off to preserve volatile memory.
- Perform a memory dump of the infected host to recover in-memory VBScript code and C2 configuration.
- Use the indicators of compromise listed in the Technical Analysis section to scan the entire environment for additional infected devices.
- Format the hard drive and reinstall Windows and applications from verified clean media. Do not rely on system restore points.
- Implement an organization-wide password reset covering all local administrator accounts, domain user accounts, and service accounts.
- When restoring backups, ensure the backup predates the suspected compromise date. Scan all restored files for malicious scripts or macros.
Microsoft Defender Antivirus automatically removes threats as they are detected. However, many infections can leave remnant files and system changes. Updating your antimalware definitions and running a full scan might help address these remnant artifacts.
You can also visit our advanced troubleshooting page or search the Microsoft virus and malware community for more help.
