MSIL/Kryptik.MVB!tr is a generic detection for a downlaoder Trojan. Since this is a generic detection, this malware may have varying behaviour.
Some of the MSIL/Kryptik.MVB!tr samples link to the Fareit (aka Pony) malware.
Below are some of the observed characteristics/behaviours:

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.