Attackers appear to have compromised tens of thousands of Web sites using a security weakness in sites powered by the forum software vBulletin, security experts warn.Report: 35,000 vBulletin Sites Easily Hacked Through Failure To Follow Security Advice [krebsonsecurity.com]

Internet Brands Inc. warned users that failing to remove the “/install” and “/core/install” directories on sites running 4.x and 5.x versions of the forum software could render them easily hackable.