DoS attack: FIN Scan from Microsoft

Since a few weeks we have a new satellite dish operational, providing fast internet thru the 
Astra -3 satellite. I had hoped the 8-fold increase of bandwidth would solve the old problem 
of a netgear router not receiving date/time signals, but NO, it is still Jan 01, 2003.

What is new and utterly annoying is a relentless attack from a Microsoft server in Singapore.
I reported the abuse and asked for an explanation but received only an automatic response.
Not only do I have to pay for every byte they send me, but as you can see it also disrupts
normal operation.
Is there anything I can do to stop this?


There are now 19 log files in my inbox containing only lines like this:

[DoS attack: FIN Scan] attack packets in last 20 sec from ip [111.221.77.151], Wednesday, 
[email failed] internet connection is dropped, Wednesday, Jan 01,2003 13:11:27
[DoS attack: FIN Scan] attack packets in last 20 sec from ip [111.221.77.151], Wednesday, 
[email failed] internet connection is dropped, Wednesday, Jan 01,2003 13:11:05
[DoS attack: FIN Scan] attack packets in last 20 sec from ip [111.221.77.151], Wednesday, 
[email failed] internet connection is dropped, Wednesday, Jan 01,2003 13:10:43
[DoS attack: FIN Scan] attack packets in last 20 sec from ip [111.221.77.151], Wednesday, 
[email failed] internet connection is dropped, Wednesday, Jan 01,2003 13:10:22
[DoS attack: FIN Scan] attack packets in last 20 sec from ip [111.221.77.151], Wednesday, 
[email failed] internet connection is dropped, Wednesday, Jan 01,2003 13:10:00
[DoS attack: FIN Scan] attack packets in last 20 sec from ip [111.221.77.151], Wednesday, 
[email failed] internet connection is dropped, Wednesday, Jan 01,2003 13:09:40