Since I was curious… A graph of spamming IPs I’ve encountered in the past 14 days (1,075) by country (78 total).
It’s only showing the top 11. (Excel’s decision.) Note that, as much as people love to blame China for spam (they are #1), the US is #9. (47 IPs, to China’s 139.) You could get the raw data (generated real-time) if you wanted to do your own analysis; Excel’s Pivot Tables proved quite handy in sorting and graphing the results. (Though I wish it was slightly easier to only include 10 values, yet have the values be for the whole data set… The top 10 account for less than 75% of total spam.)
I’d estimate that about 1,070 of these 1,075 IPs, by the way, are infected desktop machines. A new reason to keep your anti-virus current: so you stop sending spam!