According to the report, December's daily average for spam was around 30% less than in September; however spam activity increased by 45% just prior to the report's publication. The average amount of spam for the fourth quarter of 2010 was 83% of all email sent worldwide, down from 88% in the third quarter. The number of zombies active in the fourth quarter was on average 15% less than in the previous quarter.
"An inactive botnet is like an idle factory, a money-losing proposition for spammers," said Asaf Greiner, Commtouch vice president of products. "We have seen situations where after a lull in spam or malware distribution a new tactic was introduced. Threat experts are wise to continue following changes in network behavior in order to proactively block new threats."
Other highlights from the report include:
- Spam levels averaged 142 billion spam/phishing messages per day during Q4 compared to the 198 billion spam/phishing messages per day during Q3.
- Approximately 288,000 zombies were activated daily, a significant decrease as compared to 339,000 during Q3.
- The most popular spam topic in Q4 was pharmacy ads (42% of all spam).
- For the fifth quarter running, pornography/sexually explicit material is the website category most likely to include malware.
- India keeps its title for the third quarter in a row as the country with the most zombies - 17% of all zombies worldwide.
- Streaming media/downloads continues to be the most popular topic for blog creators in the Web 2.0 sphere of user-generated content.