After installing KB2585542 if you browse to an SSL webpage when going through a proxy you may receive an error that says, “Unknown Host. Description: Unable to locate the server named “localhost.localdomain” – the server does not have a DNS entry. Perhaps there is a misspelling in the server name, or the server no longer exists. Double-check the name and try again.”
According to security bulletin MS12-006, “This security update resolves a publicly disclosed vulnerability in SSL 3.0 and TLS 1.0. This vulnerability affects the protocol itself and is not specific to the Windows operating system. The vulnerability could allow information disclosure if an attacker intercepts encrypted web traffic served from an affected system. TLS 1.1, TLS 1.2, and all cipher suites that do not use CBC mode are not affected.”
In my case the workaround was to uninstall the patch. Once the vendor of our proxy server came out with a patch for their system we were able to install the patch back on the computers.