A zero-day flaw being used in targeted attacks against organizations worldwide has security experts worried that the threat could spread further. Concerns about additional attacks using the so-called “LNK” vulnerability in Windows machines via USB devices and fileshares prompted the SANS Internet Storm Center today to raise its Infocon alert level to “yellow” Microsoft has issued a security advisory that points to a flaw in Windows Shell, which was being used along with a family of malware called Stuxnet. The number of machines hit so far is only in the tens of thousands, according to some estimates.”]