VBA/Agent.BE50!tr.dldr

Analysis

VBA/Agent.BE50!tr.dldr is a generic detection for a type of macro downloader trojan that downloads the Locky ransomware onto the compromised computer. Since this is a generic detection, files that are detected as VBA/Agent.BE50!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/Kryptik.FUJR!tr .


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


• It attempts to connect to the following URLs:
  
  • hxxp://lost{Removed}.top/admin.php?f=1.dat
  • hxxp://tsiv{Removed}.com.vn/system/logs/.../1
  • hxxp://long{Removed}.com.vn/image/flags/.../1

Below is an example of its Ransom notes and infected document:

Figure 1: Infected document.

Figure 2: 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.