MSIL/WannaCry.6809!tr.ransom is a generic detection for WannaCry .NET Ransomware.
Below are some of its observed characteristics/behaviours:

  • This is a .NET version for Ransomware WannaCry which has the same characteristics/behaviours as other versions of WannaCry. Generic description for WannaCry : W32/WannaCry.7E25!tr.ransom.

  • Below is an illustration of 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.