Half a million Android phones in China have been infected by a text message worm, according to security firm McAfee.

The worm is said to access a user’s phonebook and sends out malicious links to their contacts, before asking potential victims to install a trojan.

Michael Zhang, security researcher at McAfee, said: "According to reports, the author of this malware is a college student who created this malware just to prove he can do something.

"[It] seems like a curious way to impress people."

The trojan allows the hacker to read a user’s texts, as well as send messages and steal a user’s contact list.

Should the hacker obtain a user’s identity card number and name it would also be possible for them to access a bank account in China, according to Zhang.

Two versions of the virus are said to exist, one with and one without the worm.

Google has been contacted for comment.