Based on a report from Pulse Secure, almost one million malicious applications were produced for mobile devices last year. The 2015 Mobile Threat Report, published by the company’s Mobile Threat Center, analyzed over 2.5 million mobile applications and discovered a 391 percent increase in malicious programs since 2013. 

The primary target of the malicious software was the Android operating system, accounting for 97% of all malicious programs discovered by the researchers. As Android currently owns 85 percent of the global smartphone market and is expected to grow in 2015, the distributors of malicious software are focusing on the most popular OS. Broad distribution tactics can maximize the percentage of users infected and increase profits for the distributors. The majority of the malware analyzed in the report attempted to acquire immediate profit for its proprietors, known as a shotgun-type strategy. 

The most popular malware infecting mobile devices fell into the categories of trojans, adware, and potential unwanted programs (PUPs). The official Android store, Google Play, did not seem to be affected. Forbes reports that only 0.1 percent of apps sold on the Google Play store carried potentially malicious components. Most of the infected applications originated in third-party app stores in the Middle East and Asia.

A report in PC World attributes Android’s growth to an increased “demand for low-cost smartphones across most major regions such as China, India and Africa.” As consumers of mobile devices in these countries are more likely to utilize local, third-party app stores and Android’s market share continues to grow, the number of malicious applications affecting mobile devices is expected to increase.