A zero-day flaw being used in targeted attacks against organizations worldwide has worried that the threat could spread further. Concerns about additional attacks using the LNK vulnerability in Windows machines prompted the SANSInternet Storm Center to raise its Infocon alert level to yellow, up from green, or normal, status. The SANS Institute has discovered a scareware campaign targeting Mac OS X machines using an installer signed with a legitimate Apple developer certificate.
Source: https://threatpost.com/windows-zero-day-expected-be-bad-072010/74232/