Massive growth in botnets

Stephen Withers
Wednesday, 06 May 2009 13:15

Business IT - Security

Security vendor McAfee reckons nearly 12 million more PCs were recruited into botnets during the first quarter of 2009.

Botnets are largely responsible for the spam you receive each day.

The uptick in the incidence of 'zombie' PCs has occurred as spammers seek to recover from last year's takedown of McColo, a hosting provider that apparently wasn't too fussy about its clients or what they were doing.

While spam levels are still lower than they were in 2008, the 'industry' has largely rebuilt since McColo was disconnected and McAfee estimates that volumes are already around 70 percent of previous levels.

63 percent of the new zombies come from 10 countries: US, China, Australia, Germany, UK, Brazil, India, Spain, South Korea, and Russia.

"One notable mover is Australia, which failed to make the top 10 in the third quarter of 2008," said McAfee officials.

"In two quarters it has rocketed up to the number three spot, accounting for six percent of all new zombies. The 'Land Down Under' is proving to be fertile ground for zombie recruiting."

But the top ten sources of spam aren't quite the same: US, Brazil, India, South Korea, China, Russia, Turkey, Thailand, Romania, and Poland.

Computers in the US are the source of more than one-third of the world's spam, according to McAfee's figures, but the biggest increase comes from India. That nation accounted for 4.2 percent of spam in 4Q08, but 6.9 percent in 1Q09.

Another worrying security trend is the increase in the use of legitimate sites for spreading malware:

"Ten or more years ago, it seemed you could remain safe by simply staying away from certain content, but today threats seem to find us regardless of where we browse. Any website that can be exploited (via any of numerous vulnerabilities) will be... If a high-traffic website is vulnerable, then it is not a matter of whether it will be exploited, but when."