1. How are you being accesssed? (how do you know?)
I have a firewall. It alerts me whenever an IP like 61.2.228.xx tries to access my SMTP,POP3 and Back Orifice Port. Next time I will save the log and show.

2. What are you doing when this happens?
Nothing

3. Do you have a static IP address? (check it, don't believe what your ISP tells you)
No.

P.S. It was a BHO. However I dont think there is any wrong in using proxies. If you dont want to help me, I shall try it on my on and let you people know.