Many Google Android owners have found that their phone has been infected with a "Trojan" virus; which may steal money through text messages. This increases concerns that researchers have about the security of smart phones. Russia-based Kaspersky Lab, an anti virus software company, said the malicious code, which poses as a harmless media player application, has been infecting Android devices and sending text messages to premium-rate numbers. "We consistently advise users to only install apps they trust," said Jay Nancarrow, a Google spokesman. "In particular, users should exercise caution when installing applications outside of Android Market." Many anti virus software companies have been trying to strengthen their mobile arsenal against the threats.