Google's Postini reports that August set a record for the number of viruses blocked in a single day: 188 million. Postini team members Adrian Soghoian and Adam Hollman say this may indicate an upcoming spam surge:
The spike in malware attacks during August suggests that we might see higher levels of spam moving forward into Q4 as botnet "seeds" planted during this time begin to take action.
Indeed, Microsoft's Security Intelligence Report volume 9 reported that botnets are the biggest source of cyber crime in the world today. Georgia Tech Information Security Center's 2011 Emerging Cyber Threats Report predicts botnets will continue to be a significant threat next year.