One in three users infected with malware

Despite a drop in overall infection rates, nearly one out of every three PCs carries malware according to Panda Labs.

The security firm said that overall 32 percent of users it surveyed in 2012 were infected with malware, down from 38 percent in 2011. China was the most infected country, with 54 percent of systems infected. South Korea was second, followed by Taiwan, Turkey and Honduras.

Despite the overall drop, researchers found that certain attack techniques were becoming more popular with cybercriminals. Trojans made up 76 percent of attacks in 2012, up from 66 percent the previous year.

"It seems that cybercriminals have managed to infect more computers with Trojans this year than in previous years," the company said.

"One of the reasons for this growth is the increased use of exploit kits such as Black Hole, which are capable of exploiting multiple system vulnerabilities to infect computers automatically without user intervention."

The company also found that Android remains the most popular target for mobile attackers, despite efforts by Google to improve application security. Panda acknowledged that while Google claims a 40 percent drop in malicious downloads due to tighter Play Store screening, Android remains a top target for infection.

"Android is potentially exposed to far more security risks than its biggest competitor (iPhone and its iOS), as it allows users to get their apps from anywhere their want," the company said in the report.

"However, using the official Android marketplace is no security guarantee either, as it has also been targeted by cyber-crooks luring users into installing Trojans disguised as legitimate apps."