Spam continues to take over online communications as new data suggests that it accounted for 94% of all email traffic last December. Research by Postini shows a 147% overall growth in spam levels in 2006, due to increasingly sophisticated schemes and bot networks.

The current trend is for attackers to combine techniques and build massive botnets that increase their spamming capacity. It is estimated that attackers now use a million computers to coordinate malicious spamming campaigns, while Google’s Vint Cerf has recently suggested that almost 40 million Internet-connected computers worldwide could be infected by Trojans.

The growth of botnets has now reached dangerous levels, as the system uses newly acquired bandwidth to spread even further by means of Trojans and viruses that commandeer new computers. Security company Prolexic has released data which suggests that China is the world’s most affected country and Asia now has half of the world’s infected machines. According to Postini these new massive and more sophisticated criminal networks have already shown their capability by raising the number of virus attacks twenty-fold in two short bursts at the end of 2006 and in January 2007. However, as criminals deploy new and better-protected botnets, levels of spam and virus mailings could be setting new records soon.