I have been getting messages from Safari when I am on commercial sites where I am sure that I have typed in the address correctly. Messages say that the website was signed by an unknown certifying authority and my personal information may be at risk. Th

Question

Am getting daily messages from Safari warning me that I am on a website with an unknow certifying authority and my personal information may be at risk.
Happens when in Cox webmail and when I am visitying a legitimate site, and I have typed in address correctly such as Citibank rewards site.
Have 3 choices, "Show Certficate" "Cancel" or "Continue". Screen is frozen and cannot exit Safari without acknowledging the message or clicking escape. I had been clicking continue, but after a month or more of many such messages decided to ask Cox.  They say it is a virus.  Was I careless in clicking continue?  What do many messages like this mean?  they can't all be unknown certifying authorities can they?

Answer 1

Take each of the following steps that you haven't already tried. Stop when the problem is resolved.
1. Are the current date (including the year) and time shown on your system clock? If not, correct them and test.
2. Check that the following files exist:
/System/Library/Keychains/SystemCACertificates.keychain
/System/Library/Keychains/SystemRootCertificates.keychain
If they don't, restore them from a backup or reinstall OS X after backing up all data.
3. Disable any third-party firewall, "security" software, or network filter. Test.
4. In some versions of OS X, Parental Controls has a bug that prevents loading of secure websites. Turn it off.
5. The process by which OS X checks the validity of root SSL certificates doesn't work behind the authenticating SOCKS proxies used on some enterprise networks. If applicable, contact your network administrator. The proxy server may need to have its settings changed.
6. Launch the Activity Monitor application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Activity Monitor in the icon grid.
Select All Processes from the menu in the toolbar of the Activity Monitor window, if not already selected. Enter "ocspd" (without the quotes) in the "Filter" text field. Is a process with that name listed?
If not, back up all data, then select
Go ▹ Go to Folder
from the Finder menu bar. Into the text box that opens, copy the following line of text:
/var/db/crls
From the folder that opens, move these two files to the Trash:
crlcache.db
ocspcache.db
You’ll be prompted for your administrator password. Reboot, empty the Trash, and test.