A new version of the malware that crippled Windows PCs last February sidesteps safeguards designed to block rootkits from hijacking machines running 64-bit editions of Windows, according to security researchers.

"A new era has officially dawned; the era of x64 rootkits," said Prevx researcher Marco Giuliani in a post to the company's blog yesterday.

Microsoft has released a beta refresh of its Windows 7 and Windows Server 2008 R2 Service Pack (SP) 1 to selected PC and Technology Adoption Program (TAP) partners, company officials confirmed on August 30.

Microsoft Chief Operating Officer Kevin Turner at the Financial Analyst Meeting today has revealed that the Redmond based company is planning to drop a beta version of Internet Explorer 9 sometime in September of this year.

Security firm Panda Security's antimalware laboratory PandaLabs has discovered that in 2010, 25 percent of new worms have been specifically designed to spread through USB storage devices connected to computers.