According to a study conducted by Microsoft, more 2 million PCs in the US have been hijacked by botnets in the first six months of 2010.
The statistics show that the number of botnet infected PCs have more than doubled over the last year.
The company said that the research had been done to highlight to the world how easily a computer could be affected by a botnet, and the kind of implications botnet infections can have.
The US is followed by Brazil in terms of botnet infected PCs, which were pegged at 550,000. Meanwhile, in South Korea 14.6 PCs in every 1000 PCs were infected by botnets.
The report comprises of Microsoft's in-depth study into the nature of botnets and the level at which they were used to facilitate cyber crime.
A network of botnet infected PCs is used by hackers to spread spam, phishing e-mails and perpetrate attacks on websites.
Hackers also use the botnet to acquire sensitive information from infected PCs, which is later sold to underground auction sites and companies who want to access such data.