Spam levels have risen by an astounding 141% since March, according to a new report just released. Botnets are largely responsible for the rise and the number of computers added to botnets has risen to 14 million, a 16% increase. Roughly 150,000 computers a day are infected by malware and added to botnets.

Not surprisingly, South Korea was hardest hit, reporting a 45% increase in botnet activity over last quarter. Most of that comes from the massive DDoS attack that hit the country earlier this month. The same attack also affected most government websites here in the U.S. as well as the New York Stock Exchange and many major business sites.

The report also found that spam volumes grow by over 117 billion e-mails a day, and that malware isn’t far behind. Malware writers are now offering their products to botnet operators as a way to increase their reach.
Malware that takes advantage of Windows’ Auto-Run feature is also on the rise. The malware lets hackers take over the feature even if the victim hasn’t clicked on anything. Such attacks have far outpaced more well known malware such as the Conficker virus.

Spam and attacks on social networks also rose. Facebook, Twitter, and MySpace are all heavily exploited by cybercriminals to spread spam, malware and conduct phishing attacks. In May alone, spam on social networks led to nearly 4500 files containing the Koobface virus.