The recent discovery of a large number of malicious mobile phone programs should raise concerns throughout the wireless industry, according to a virus tracker.

Mobile phone antivirus software company SimWorks reported on Wednesday that 52 new Trojan horses are hidden inside several different mobile phone games and other readily available mobile phone software. While the software appears to be safe to share or use, the Trojans actually contain malicious software that crashes many critical mobile phone system components.

The Trojan horses target only mobile phones that use Symbian, an advanced, or "smart phone," operating system that competes with similar software from Microsoft to bring PC-like capabilities to phones. To date, no phones have been affected, according to Aaron Davidson, chief executive officer of SimWorks.

Smart phones continue to represent just a tiny percentage of overall mobile phones sold. But many analysts and mobile phone industry insiders say that as these advanced operating systems become more common over the next decade, mobile phone viruses will become more widespread as well.

While the damage is negligible so far, the recent warnings from SimWorks and security specialist F-Secure are raising alarm bells in the wireless industry. The latest report brings the total number of known Symbian Trojan horses to more than 100.

Virus writers appear to be producing malicious mobile phone programs at an unprecedented pace, as well. Between June and October of 2004, a new Symbian virus would emerge once a month. Now that pace is once a week, Davidson said.

"Putting together this many Trojans would be very time-consuming and shows a considerable amount of determination on the part of the writer or writers," Davidson said. "Even if the original writer or writers never intended for them to be released into the wild, the fact that they are making their way through the writing community means that someone at some point will definitely release them."