A new report has suggested that malicious apps may have cost Android users as much as $1m during 2011.

The report comes from Lookout Mobile Security and its Mobile Threat Network, which collects information from one million apps and 15 million devices worldwide.

The report found that the likelihood of encountering malware on an Android device went up in 2011 compared to 2010, rising from 1% to 4%. Not huge figures, but it is still a sharp rise and confirms what many other companies have suggested – that threats to mobile devices are on the rise.

Lookout has identified what it calls "mobile pickpocketing" – dodgy Android apps that can steal money from users by signing them up for premium-rate text message services. The company name-checked GG Tracker as one such app. Lookout estimates that more than $1m has been stolen from Android users via this method.

2012 will see more apps that target users in this way, Lookout Mobile Security believes.

"2011 was a watershed year in terms of the types threats we saw emerging. Threats had greater sophistication and were deployed using more innovative and efficient distribution methods," said Kevin Mahaffey, Lookout’s co-founder and chief technology officer. "In 2012, we expect to see the mobile malware business turn profitable. What took 15 years on the PC platform has only taken the mobile ecosystem two years."

Apple’s iOS devices are not safe either. Lookout predicts that 2012 will see more malware aimed at that platform, as well as Android, because of the vulnerable nature of mobile phones. "Due to the difficulty of updating software and patching vulnerabilities on mobile phones, malware writers will continue to exploit iOS and Android OS at a pace greater than vulnerabilities can be resolved," the report says.

CBR recently profile the top five security apps for mobile devices, which featured Lookout Mobile Security. Read the full list here.