Popular mobile games such as Angry Birds and Monkey Jump are being illegally copied and repackaged with code designed to steal personal information or perform other malicious functions, according to a study due to be released soon from Lookout Mobile Security.Although companies such as Google and Apple have dedicated marketplaces for applications that have been approved, there are an increasing number of third-party sites for downloading applications, said John Hering, CEO of Lookout Mobile Security, on the sidelines of the Mobile World Congress in Barcelona on Monday.As part of its study, called the App Genome Project, Lookout examined applications in two alternative Android application marketplaces aimed at Chinese speakers. Eleven percent of the applications were merely clones of legitimate applications stuffed with other code, some of which have the potential to be malware, Hering said.One of the most commonly cloned applications is Monkey Jump, Hering said. It isn't immediately clear what some of the code does in those tampered-with applications, but Hering said there are a few possibilities, such as creating a botnet or sending text messages to premium rate numbers.Other possibilities are that the applications are then used to sign up to advertising schemes, with the profits channeled to miscreants rather than the legitimate publisher."We worry that this is the beginning of something very substantial," Hering said. "If you're downloading from a third-party alternative market, it doesn't mean it's a bad idea but you need to really take caution with what you're doing. It's hard to know what's in there or what isn't."In December, Lookout discovered a piece of Android malware called "Geinimi" that contained functions similar to botnet code designed for a PC: It communicated with a command-and-control server and can issue commands to a phone remotely, such as to install or uninstall software.Hering said since that time, Lookout has discovered many more variants of Geinimi, indicating that hackers are still actively working on its code. Geinimi targeted Chinese-language speakers, and its true malicious function hasn't been determined."It's clearly not a one-off thing," Hering said. "It's becoming a bigger and bigger issue."On the bright side, Hering said the App Genome Study has also found that developers seem to be more aware of security and privacy issues. The number of applications in both the Android Market and Apple's App Store that access a person's location and contacts information has gone down slightly over the past six months. Many times applications don't need that data, but developers were eager to use an API (application programming interface) that allowed access."We believe that is due to the fact that developers are becoming more educated about privacy," Hering said. "Developers are starting to be privacy- and security-conscious for their users."Hering is due to speak later this week at the RSA conference in San Francisco.