Am I being hacked ?

I have a home PC guarded by Zone Alarm pro which is suggesting that an unknown programme is trying to access a remote pc. The programme Microsoft VM Command Line has requested internet access but does not seem to be associated to any current software…when checked at Zone alarm site the programme name appears changed – something like
” MICROSOFtYYYEY4343″. The programme is also not recognised at Microsoft knowledge base. Is this a Trojan? I have scanned using Norton Anti Virus but it suggests all is in order. If it a Trojan – – what should I do
Also what is tracker-tracker? this appears linked to the problem.