Earlier this year, a virus known as Red Browser surfaced. It's sent to a cell phone or a smartphone via Short Message Service or Multimedia Message Service and corrupts data.

Red Browser is one reason software vendors are starting to offer more types of security features and products for more kinds of mobile devices. This week Symantec rolled out Mobile AntiVirus 4.0, designed to protect mobile devices running Windows Mobile 5.0, including smartphones such as Motorola's Moto Q, from threats transmitted through e-mail and MMS; downloaded from memory cards, a cellular network, or Wi-Fi; transmitted by Bluetooth; or beamed over infrared connections. Symantec previously offered software only for mobile devices running the Pocket PC version of Windows Mobile.

Sybase iAnywhere, meanwhile, this week made available enhanced versions of two core components of its Information Anywhere Suite, designed to let companies synchronize data between mobile devices and enterprise software from BMC, Business Objects, Lotus, SAP, and others. Its Afaria management and security software can now be used for Windows Mobile-based devices, and its OneBridge software for enabling mobile e-mail and applications now lets IT managers encrypt or lock down mobile devices.

Security continues to be the top concern for IT managers thinking about giving workers access to business applications on mobile devices. Several types of mobile security threats have surfaced in recent months. Snoopware, a mobile version of spyware, infects a cell phone or smartphone and allows an attacker to listen in on a phone conversation. In April, a company called FlexiSpy began selling software that connects to mobile phones through Bluetooth and secretly records all activity on phones. "It poses a huge threat to mobile users, putting a stranger in your bedroom and a competitor in your bedroom," says Paul Miller, managing director of mobile and wireless for Symantec.

Antivirus software isn't always enough, though. Mobile devices are constantly communicating with wireless networks whether it's cellular, Wi-Fi, or Bluetooth. Mobile devices should be protected by a firewall, said Shane Coursen, senior technical consultant at antivirus software company Kaspersky Lab, during a panel discussion at the Mobile Business Expo show in Chicago on Wednesday.

The good news is more companies are taking mobile security seriously. "Interestingly enough, we find that smartphones are often better secured than laptops," says Rick Hartwig, director of product management at Good Technology, a provider of wireless messaging. Companies purchasing smartphones for their employees are asking for the latest encryption tools and antivirus software and setting up security policies to protect their data, Hartwig says.