Mobile users in Thailand should avoid downloading applications from small retail kiosks to protect themselves from the risk of viruses, warned the Advanced Info Service in an interview with the Bangkok Post.

Pratthana Leelapanang, vice-president of Value-Added Service at AIS, said the company had been closely monitoring the growing mobile-security threat for the past two years given the fast-rising popularity of BlackBerry, iPhone and Android devices.

He said AIS and its peers were spending more on network security these days because operators have essentially become Internet service providers rather than providing just voice services.

Leelapanang said last year there had been reports of an unknown threat from outside the country to "bomb" its network traffic in hopes of disrupting or hacking the system.

Fortunately, the company was able to block the virus with no service interruption.

According to the Bangkok Post story, the threats were particularly evident among users who downloaded applications illegally from small retail kiosks throughout shopping areas.

Leelapanang said AIS is educating users to download applications from only authorized services and is providing mobile anti-virus software, such as F-Secure and McAfee, to users who request them.

People who use mobile devices need to change their mindset about security, said Prinya Hom-anek, secretary of the Thailand Information Security Association (TISA) and president and founder of ACIS Professional Center.

"Once a phone has been compromised with spyware, it is not your phone anymore," he said. "A hacker then can take control of your phone by eavesdropping or tapping a voice message, including your chat, SMS, e-mail or webcam, to carry out data theft and even locate your position anywhere in the world. Thus, any transaction via a mobile phone will be re-delivered to a hacker promptly."