Microsoft windows graphicComputer security experts were grappling with the threat of a newweakness in Microsoft’s Windows operating system that could put hundreds of millions of PCs at risk of infection by spyware or viruses. The news marks the latest security setback for Microsoft, the world’s biggest software company, whose Windows operating system is a favourite target for hackers. “The potential [security threat] is huge,” said Mikko Hypponen, chief research officer at F-Secure, an antivirus company. “It’s probably bigger than for any other vulnerability we’ve seen. Any version of Windows is vulnerable right now.” The flaw, which allows hackers to infect computers using programs maliciously inserted into seemingly innocuous image files, was first discovered last week. But the potential for damaging attacks increased dramatically at the weekend after a group of computer hackers published the source code they used to exploit it. Unlike most attacks, which require victims to download or execute a suspect file, the new vulnerability makes it possible for users to infect their computers with spyware or a virus simply by viewing a web page, e-mail or instant message that contains a contaminated image. “We haven’t seen anything that bad yet, but multiple individuals […]