Mobile security firm Lookout said that 27 apps have been found in Android Market which contain instances of RuFraud, which is malware that sends premium SMS messages from an infected handset – at the expense of the owner.

It said that there has been a “rash of premium SMS toll fraud apps in the last few months,” primarily targeting users in Europe. These have often purported to be downloaders for well known apps, and while initially located on file sharing sites and alternative app stores, they have now crossed-over into Android Market.

According to the company, initially RuFraud was noted in horoscope apps, with a “fairly hidden” reference to charges in the terms of service. This was later extended to include wallpaper apps for popular movies, and downloaders for popular games such as Tetris, Angry Birds and Cut the Rope.

It was noted that “Google responded quickly to our reports and pulled these apps from the Android Market.” This took place when the number of downloads was low.

A recent report from security specialist McAfee said that Android is “the primary target for new mobile malware,” with nearly all new attacks targeting this platform.  Several other discoveries of infected apps in Android Market were reported widely earlier this year, although it is not clear how many end users have been affected by problems.