Symantec's

Symantec's estimates record an even steeper drop, going from about 140 billion spam messages a year ago to less than 60 billion.

Help File: Less spam 2011

Symantec's estimates record an even steeper drop, going from about 140 billion spam messages a year ago to less than 60 billion.

Help File: Less spam 2011

At the same time, the malware fed false signals to the plant's computer system so the operators thought the machines were working normally, Symantec's experts found.

Iran's Natanz nuclear facility recovered quickly from Stuxnet cyberattack Joby Warrick 2011

And even in the current environment, spam still makes up a dismayingly large fraction of all e-mail: 82.5 percent according to M86, just less than 80 percent in Symantec's data.

Help File: Less spam 2011

Symantec's new technology, which it calls Quorum, examines the software running on the computers of millions of volunteers, who remain anonymous, to spot possible threats.

The Winners, Category by Category Michael Totty 2010

At the same time, the malware fed false signals to the plant's computer system so the operators thought the machines were working normally, Symantec's experts found.

Iran's Natanz nuclear facility recovered quickly from Stuxnet cyberattack Joby Warrick 2011

At the same time, the malware fed false signals to the plant's computer system so the operators thought the machines were working normally, Symantec's experts found.

Iran's Natanz nuclear facility recovered quickly from Stuxnet cyberattack Joby Warrick 2011

At the same time, the malware fed false signals to the plant's computer system so the operators thought the machines were working normally, Symantec's experts found.

Iran's Natanz nuclear facility recovered quickly from Stuxnet cyberattack Joby Warrick 2011

At the same time, the malware fed false signals to the plant's computer system so the operators thought the machines were working normally, Symantec's experts found.

Iran's Natanz nuclear facility recovered quickly from Stuxnet cyberattack Joby Warrick 2011

Brazil has supplanted Germany as the globe's No. 3 origination source of malicious net traffic, whileIndia has zoomed to No. 5, according to rankingsreleased today in Symantec's 2009 Global Internet Security Threat Report.

Symantec rankings: PCs in Brazil, India fueling more cyberattacks 2010