It's almost assuredly a false positive. That file (LAN.tfx) is truly part of total commander and is not even an executable so there's no virus.
This has happened many times in the past with various virus vendors. They look for certain signatures to identify various viruses and sometimes either due to an error on their part or just being too broad in their criteria innocent files get flagged.
There really are no legitimate windows mobile viruses in existance (yet, anyway). I don't think you have anything to worry about.
