I have been getting a lot of "blocked" messages from zone alarm fire wall telling me it has blocked packets sent to my computer and from my computer. I do not understand what is happening, and am worried someone is trying to hack my computer! Also, we have 2 computers in the house connected to the same network, and although we are not doing anything ourselves, they seem to try to send packages to each other as well.
This is the info i get from zonealarm about the suspected packets sent to me:
(not the ones from my 2 computers)
Protocol: UDPProgram: svchost.exesource IP: similar to mine except for the last digitsDirection: Incoming

RoutedSource DNS: api.home
And from what is trying to send from my computer to them:
Protocol: TCP (flags:S)My computer is listed as the source and the direction is outgoing.
I have scanned my computer but cannot find any viruses.
What could this be?
Thanks for any help!!!

Operating System:Windows Vista Home Basic
Product Name:ZoneAlarm (Free)