Google recently removed 10 applications from the Android Market, all of which contained malicious code disguised as add-ons to one of the most popular apps of all time.

According to Gadget Lab, each of the removed apps posed as a cheat or an add-on to Angry Birds, the much-lauded mobile application created by Finnish game development studio Rovio.

A number of the apps in question contained a spyware program called Plankton, which connects to a remote server and uploads phone information like the IMEI number, browser bookmarks and browsing history.

Xuxian Jiang, an assistant professor of computer science at North Carolina State University, initially discovered the malicious applications last week, and reported them to Google. Google suspended the questionable applications the same day, “pending further investigation.”

Jiang found malicious programs other than Plankton in his research. YZHCSMS, for example, is a Trojan horse virus that jacks up your phone bill by sending large amounts of SMS messages to premium numbers. Jiang says apps containing the virus were available on the Android Market for at least three months before Google pulled them.