If you use (gag) Internet Explorer, there is a critical vulnerability under active exploit and you should patch your system immediately.
Online attackers are actively exploiting a vulnerability in Internet Explorer that allows them to execute malicious code on computers that visit booby-trapped websites, researchers said in an advisory that underscores the importance of installing a Microsoft patch as soon as possible.
More: http://arstechnica.com/security/2012/06/windows-users-patch-now/

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