It's apparently Darkmailer2 month in Canada. One company got a grip on it, and two got much worse, in the December 2012 for Canada.
AS 7788 MAGMA-COMM, bought in 2004 by PRIMUS Telecommunications Group, peaked in the second week and then got a grip on its darkmailer2 spamming. AS 11342 PATHWAY really gave AS 32613 IWEB-AS a run for its money; both seem to have a darkmailer2 problem. Pathway went from 2,871 spam messages seen by CBL in November 2012 to 21,593,775 in December 2012: that's 7,521 times. However, iWeb once again won the spam-spewing month in Canada!
Congratulations to the four dropouts, especially AS 16532 ASB2B2C, which
Of the 160 site(s) we tested on this network over the past 90 days, 8 site(s), including, for example, chateaudevalloubiere.com/, massagesparisrelaxation.fr/, gescomplus.ca/, served content that resulted in malicious software being downloaded and installed without user consent.
The last time Google tested a site on this network was on 2013-01-30, and the last time suspicious content was found was on 2013-01-23.
Maybe this reduction in spam volume indicates a new leaf for ASB2B2C.