Rootkits have emerged as one of the biggest security challenges over the past six months, according to the latest report from security specialist F-Secure. Mobile malware could also pose a significant threat in future.

F-Secure’s data security report for January to June 2006 highlights the spread of rootkits, which intruders install on computers to conceal their presence and allow them to gain access to systems undetected.

Richard Hales, UK and Ireland country manager at F-Secure, said more action is needed to deal with the threat. “If you can hide malware on a PC, then the processes can sit running in the background without being detected by antivirus software,” he said. “Until every antivirus vendor provides rootkit protection, they’ll continue to be a useful tool for [malicious users].”

There are currently more than 185,000 viruses in existence, but most companies have antivirus systems to guard against the majority of these threats, said Hales. However, more and more mobile viruses are being discovered – over 200 have been identified – and these may pose a bigger challenge to firms, according to Hales.

“Smartphones are the only bit of an organisation that isn’t protected,” Hales warned. “IT managers have gateway, desktop and server scanning, but people can plug their mobile in and sync up with Outlook. It’s only a matter of time before mobile devices are used to get malware onto the corporate network, and it’s a danger I’d be concerned about as an IT manager.”