The company selling a mobile phone spy application that has been labeled malware by F-Secure says the software isn't malicious or illegal.

F-Secure software recently began blocking a commercial application called FlexiSpy that bills itself as the world's first spy software built for mobile phones.

When FlexiSpy software is loaded onto a Symbian mobile phone, it sends all text messages that are sent and received, as well as call details, to FlexiSpy servers. Users can log on to the servers via the Internet to read the messages and view the call records. The problem, says F-Secure, is that the phone owner may not know the program has been installed and can't uninstall it.

"We're convinced that this could be used for malicious and illegal purposes in so many ways that we made the decision to flag it as malware," F-Secure Chief Research Officer Mikko Hypponen said.

Vervata, the Bangkok, Thailand, company that created FlexiSpy, argues that the product isn't a virus, a Trojan horse or malware.

"Like any other monitoring software there may be a possibility for misuse, but there is nothing inherent in FlexiSpy that makes it illegal or malicious," a Vervata spokesman wrote in an e-mail exchange. He said that the software must be consciously installed by a person, does not self-replicate and doesn't pretend to be something it's not.

He said that an uninstall option is provided so the user can uninstall the program at any time but F-Secure found that the application uninstaller doesn't work.

Hypponen also worried that a user could "beam" the program via Bluetooth to other nearby users. "If one in 100 people who received it wonders what it is and clicks on it, it would install without telling the user what the program does," he said. Going forward, the person who sent the program could read that person's text messages online. "If that's not malicious, I don't know what is," Hypponen said.

Some changes to the program could make it more palatable, he said. For instance, if the installation process clearly shows that a spy program is being installed, it could be useful for parents that might want to monitor a child's text messages, he said.

But using this type of program to spy on another person is illegal in most parts of the world, he noted. In addition, he also said that users might be concerned that the text messages and calling information is being stored on Vervata servers.

The IDG News Service is a Network World affiliate.