Paranoid spouses will find it even easier to track their partner with a new mobile spyware tool that delivers reports via email.

ePhoneTracker from Retina Software secretly monitors "every cell phone activity" before sending reports via email. Comparable commercial mobile spyware products, such as FlexiSpy, work on mobile to mobile reports. ePhoneTracker – which works on Android, BlackBerry, iPhone iOS, Symbian OS and Windows Mobile 6 smartphones – is marketed towards individuals who want to track their kids' or employees' habits as well as seeing if their spouse is cheating.

"If you think your spouse is cheating, then statistics state you are probably correct," said Gerald Carvey, VP of Product Development. "Cellphones are the primary communication tool for affairs. Our software allows you to expose the truth to see whether or not your suspicions are accurate."

Commercial spyware products are technically similar to their black sheep siblings and really only differ in that the person who pays the phone bill, if not the user, knows that calls, test and web surfing logs are being monitored. Anti-virus firms commonly detect either class of application as malign or, at very least, potentially unwanted.

Figures on the installation base of commercial mobile spyware applications are hard to come by but anecdotal evidence suggest that unsolicited mobile spyware is growing in prevalence, albeit from a modest base. More than 150,000 mobile phones in China are reportedly infected by an application called Xwodi that allows third parties to eavesdrop on mobile calls, according to Beijing-based mobile security services firm NetQin Technology.

Xwodi is a variant of FlexiSpy that is targeted at devices running the Symbian platform. The malware silently activates the conference call feature to tap into phones. It is also capable of covertly switching on a phone's microphone, to get recordings even when a user is not on a call. In addition, the malware intercepts and relays text messages. Victims may become exposed to the malware via infected MMS messages, NetQin suggests. Variants of the malware were reportedly captured by the National Computer Virus Emergency Response Centre of China. ®