Q: TBScan finds an unknown virus in the files RVK_X.COM and DECOM_X.COM.

A: Seems to be my program RVK.COM and DECOM.COM (generic virus killer and
   decryptor).  If so, these programs are protected by a self checking
   envelope to ensure the files aren't infected.  You can verfiy this by
   yourself by looking at the code at the end of the program.  You should
   see text (in German) like

...  VSS - Virus Schutz Schild (c) 1990-93 by ROSE Softwareentwicklung ...

   etc.

   As you can see TBSCAN heuristic is VERY bad, all other scanner (AVP,
   RHBVS, VSP etc.) didn't find a virus...

   BTW: You can request the latest DECOM release at my node (DECOM.RAR).