McAfee is reporting that it has seen a sharp rise in the number of PC infection and malware variants as botnet operators try to rebuild their networks after the McColo shutdown.

In the first quarter of 2009 the company’s AVERT laboratory reported 12 million new IP addresses were identified as belonging to ‘zombie’ PCs - those infected machines that are used remotely in botnets - a rise of over a million from the last quarter.

“This is the reseeding of botnets,” Jeff Green told vnunet.com during a video interview.

“We’re expecting an uptake in the amount of spam later this year as a result.”

The variations of malware are also on the rise he said. McAfee keeps a virus ‘zoo’ with a copy of every piece of malware it encounters, and had added four million new samples in the last quarter.

In 2008, the AVERT laboratory saw a sharp rise in the levels of malware in circulation, with growth rates of 270 per cent. So far this year the rate has grown by 115 per cent.

“When I got the figures I sent my team back and told them to do the calculations again,” he said.

“I thought they’d been smoking something. We’re seeing a phenomenal growth rate.”

The market for stolen information is also changing, he said. Some data thieves prefer to steal bank accounts and, rather than use them themselves, sell them on instead.

A Washington Mutual bank account containing US$14,400 was recently put on sale for US$924 he said. In some cases the sale was also backed up by a guarantee of access.

Gamers are also being targeted he said. The growth in games that allow players to trade online goods made them a tempting target, and many turn off their security software to increase their system’s speed.