Piriform has released CCleaner 4.08 which now cleans Firefox new cache also (that was introduced with Firefox 27), apart from that Piriform has enabled Intelligent Cookie Scan which was introduced with version 3.0, now by default in this version, without prior notice or mention in the release notes, you can see this option pre-selected and shown during setup, you’ve the option to opt-out by removing the check mark for ‘Enable Intelligent Cookie scan’ on that dialog.
After enabling this feature, CCleaner detects all those cookies which you use to login to websites and adds them to ‘cookies to keep’ on right side in Cookies section, see the screenshot below. You can select and delete them if you want.
This feature actually benefits you. It keeps the persistent cookies which you used to sign into websites. Very useful, when you’ve turned on two-factor authentication for Google or twitter accounts where clearing cookies for these sites from Trusted computer makes you to enter the secret code that send to your mobile during logon.