Close all browsers then:
Start, All Programs, Accessories, (Vista must: right click on Command Prompt and Run as Administrator, XP just choose Command Prompt), (Vista: Continue.) Type with an Enter after the line:
netstat -n > \junk.txt
notepad \junk.txt
This will bring up a list of TCP connections in notepad. Something like this:
Active Connections
Proto Local Address Foreign Address State
TCP 127.0.0.1:49352 127.0.0.1:49353 ESTABLISHED
TCP 127.0.0.1:49353 127.0.0.1:49352 ESTABLISHED
TCP 192.168.11.47:49157 77.234.41.51:80 ESTABLISHED
TCP 192.168.11.47:49349 213.199.179.149:40002 ESTABLISHED
TCP 192.168.11.47:49350 193.120.199.15:12350 ESTABLISHED
TCP 192.168.11.47:49351 65.55.71.46:443 ESTABLISHED
TCP 192.168.11.47:51700 67.228.86.176:80 CLOSE_WAIT
TCP 192.168.11.47:51701 67.228.86.176:80 CLOSE_WAIT
TCP 192.168.11.47:51702 23.34.78.13:80 CLOSE_WAIT
TCP 192.168.11.47:51703 23.34.78.13:80 CLOSE_WAIT
TCP 192.168.11.47:51704 173.194.33.40:80 CLOSE_WAIT
TCP 192.168.11.47:51705 23.34.78.13:80 CLOSE_WAIT
TCP 192.168.11.47:51706 23.34.78.13:80 CLOSE_WAIT
TCP 192.168.11.47:52071 157.238.74.194:80 LAST_ACK
TCP 192.168.11.47:52078 74.125.129.147:443 ESTABLISHED
TCP 192.168.11.47:52079 173.194.33.34:443 ESTABLISHED
TCP 192.168.11.47:52080 173.194.33.47:443 ESTABLISHED
TCP 192.168.11.47:52081 173.194.33.41:443 ESTABLISHED
TCP 192.168.11.47:52082 173.194.33.39:443 TIME_WAIT
TCP 192.168.11.47:52083 173.194.33.40:443 ESTABLISHED
You can ignore (or delete since you are in notepad) the ones that have 127.0.0.1:something in the Foreign Address column. Those are just local connections. Using a Browser go to:
http://www.findip-address.com/and input in the first non-local IP address from the Foreign Address column that says ESTABLISHED in the State column and then hit Find IP-Address. (Ignore the stuff after the : )
In my case it's 77.234.41.51
which gives a result of:
IP address 77.234.41.51
Hostname r-051-041-234-077.avast.com
City
State/Province
Country Czech Republic
ISP AVAST Software a.s.
Organisation AVAST cloud
Since I have the free Avast Anti-virus on my PC this is a valid connection.
Continue with each connection. You may find some multiple connections to the same location - sometimes with different numbers after the : but that is normal. As long as the IP address goes to a destination you recognize it's OK. If you don't recognize it and especially if it is not in the US that is a suspicious connection. Come back here and ask me about them.
Ron