According to SecurityCoverage Inc.'s SecureIT Quarterly Malware Report: Q2 2013 [PDF], the company's SecureIT Research team detected 39 percent more viruses in the Q2 2013 than in Q1 2013.

Of the quarter's total of 1.8 million virus detections, 82 percent were Trojans, and 25 percent exploited a Java vulnerability in their attempt to gain access.

The researchers also noted a 34 percent increase in adware such as GameVance and Hotbar. "Adware, though not generally malicious, can be a nuisance on an infected computer due to the persistence of the advertisements causing overloads and crashes," the report states. "In some cases, adware is used as a cover-up to hide more malicious activity such as virus installations, communication with command and control servers, or click jacking."

They also detected approximately 200 detections of bitcoin miner malware for the first time. "Bitcoin mining is not generally malicious, but does use all of the available memory and bandwidth ... on a computer, making it impossible to perform other actions," the report states.