RedKit exploit kit contains an API that generates new host-site URLs every hour. This feature will make it incredibly difficult to reliably block RedKit infected sites. The kit also has a feature that allows its users to upload an executable and test it against 37 different antivirus solutions. RedKit is exploiting two popular (and patched) vulnerabilities, one is an obfuscated PDF file that exploits the LibTIFF vulnerability (CVE-2010-0188) and the other is an AtomicReferenceArray Java vulnerability.
Source: https://threatpost.com/new-exploit-kit-redkit-discovered-wild-050712/76533/