Security :: Incoming Connections On 445?

Its been really bugging me that whenever I scan my connection with wireshark I see this one person sending me a SYN packet every minute on port 445. I know this is the dangerous port that the Conficker worm travels along. So far my computer seems to be immune and I know, at least on the Linux side that I can just add a rule to my ip tables to block that port indefinitely. I want to know what the next step is.

00 0c 41 b2 e4 1d 00 11 09 b2 2f 0e 08 00 45 00
00 30 91 84 40 00 80 06 d1 c7 46 4f 86 29 XX XX
XX XX 10 43 01 bd 9e 23 d6 27 00 00 00 00 70 02
ff ff 65 58 00 00 02 04 05 b4 01 01 04 02

This is one of the packet captures I am getting. After sending me this and getting no reply, all of a sudden he goes up an ip. Basically this would be the pseudocode for what it looks like hes doing on my end.

while(1){
for(int i = 1; i != 255; i++){
send_connection_attempt("XX.XX.XX." + i);
}
}

To me this looks like this guy has hijacked a computer and is using it to run a script over. He is still scanning my network as I said earlier, what should I do? Should I contact my ISP? or just nail down the hatches and make sure nothing is exposed on my network?