I had a recent look at my Active Connections and noticed:
System:
TCP Listening on: 5357
TCP Listening on: 445
TCP Listening on: 139
Everything I read seems to suggest that these are bad to have open - are they - and why are they open? Should I close them or will I lose something that I am not sure of?
Well it depends, if you check these on your PC then they are probably “LISTENING”
139 and 445 are used for Microsoft File and Printer Sharing so others can connect TO you, so in general you don’t want to have these ports open from the Internet to your PC.
Can you tell what application shows up with 5357? it has multiple hits on both good and bad processes.
So depending on your network setup it’s better to have these closed from the internet to you.
Is your PC behind a router before it accesses the internet?
… while i would block all unrequested ingoing traffic at first. use the stealth port wizard, hide me from everyone.
or make a rule in global rules, “block ip in any any”.
and block these mentioned ports for both directions and all protocolls (ip) in global rules too.