Build a big user base and the malicious-code writers will come. That's the logic that analysts and security software companies alike are following as they warn that smartphones and other mobile devices will become significant targets for security threats in 2005. In response, antivirus company Trend Micro is offering a free download and updates for one of the first software products for protecting smartphones and other handheld devices.

Trend Micro Mobile Security software is available at www.trendmicro.com/ mobilesecurity and will remain free until June 2005. On its initial release, the software supports Microsoft's Windows Mobile 2003 operating system. In January, an update will support the Symbian OS 7.0 with UIQ 2.0/2.1. The software works very much like antivirus software on a PC and also protects against SMS (Short Message Service) spam.

"Most of the threats to smartphones and other mobile devices so far have been proof-of-concept threats," says Todd Thiemann, director of device security marketing at Trend Micro. He cites the Skulls.a and Cabir.a viruses from 2004 as examples. "In 2005, especially because smartphone use is growing so rapidly, the threats will become more virulent."

That sentiment is backed by a report from IDC analysts saying that mobile devices will become significant targets for malicious code in 2005. And a Gartner report indicates that 90 percent of the mobile devices distributed by IT departments don't have any security protection. Meanwhile, officials at security company McAfee have been briefing wireless carriers about beating the risks.