I have seen an issue when scanning a Windows 2012 server. There is an existing authentication record with a domain admin that can access Windows 2003/2008 with no issues.
When I try to scan a Windows 2012 server, the scan ends with authentication failed. If I scan again it fails. Scan again, success. Scan again, fail. This happens very sporadically.
Windows Firewall is running, but I do not believe that is the issue. The firewall would have stopped the connection right away, so I would not even see the authentication failure message. I whitelisted the Qualys appliance IP addresses in the Firewall, and the same results occurred. Sporadic successes and failures. I have opened a case with Qualys, but he rep says they will have to investigate....has anyone found the root cause of this? This ONLY happens on Windows 2012 for us. Some analysis revealed that remote registry was disabled during failed scans and enabled during scans that passed. Can anyone help?