VBS/Agent.PEC!tr.dldr

Analysis

VBS/Agent.PEC!tr.dldr is a generic detection for a type of Visual Basic script downloader trojan that downloads and runs the Locky ransomware onto the compromised computer. Since this is a generic detection, files that are detected as VBS/Agent.PEC!tr.dldr may have varying behavior.
Below are examples of some of these behavior:

• It downloads the Locky ransomware as the following file:
  
  • undefinedTempundefined\[Random].exe : This file is detected as W32/Locky.KAD!tr .


• It adds the ".lukitus" extension to encrypted files.


• It attempts to connect to the following URLs:
  
  • hxxp://gbas{Removed}.ch/tJHGskdioj
  • hxxp://vinn{Removed}.net/af/tJHGskdioj
  • hxxp://graf{Removed}.com/tJHGskdioj


• Below is the malware's Ransom notes:
  

  Figure 1: Ransom notes.

Recommended Action

• Make sure that your FortiGate/FortiClient system is using the latest AV database.
• Quarantine/delete files that are detected and replace infected files with clean backup copies.