Despite the arrests of several major spammers in 2007, spam levels rose to record levels in December, accounting for 97% of all emails sent that month. Viruses accounted for .11%. Researchers at Softscan released a list of the top five viruses sent in December:

1. Phishing: 87.54%
2. Dropper: 4.76%
3. Agent: 2.19%
4. Netsky: 1.24%
5. Downloader: 0.86%

Softscan also warns that spammers will continue to dominate email traffic and that the recent arrests did nothing to deter them.

"Once again the rapid increase of spam throughout 2007 demonstrates that there is not enough deterrent for spammers to give up their highly lucrative enterprise," said Diego d'Ambra, chief technology officer at SoftScan.
"Usually, when you look through our monthly statistics, you can quickly identify the weekends or major public holidays when there is less legitimate business email sent as the spam levels jump-up.
"But in December, except for some slightly lower levels in the first week, spam has remained consistently high throughout the month."

In December 2006 spam only accounted for 90% of all email sent. With new techniques like mp3 and pdf spam, levels will most likely remain high throughout 2008.