The fact you stated IOBit claims ASC to be "easy to use and 100% safe with no adware, spyware, or viruses." would then have me pointing fingers at IOBit. Where CNET plays a part is questionable. From what I'm able to tell, the IObit toolbar is (partially) to blame.
• At the IOBit forum where one of many members complained about 'Spigot with a search settings.exe file', a moderator writes in its defense:
'First of all, it is not a required component of ASC at all. I would uninstall IObit toolbar and the other installed free applications if you don't want them on your PC. You should have unchecked that option when installing the recent ASC update if you didn't want them to be installed. I will not discuss those kind of optional extra installations, as I don't approve at all, but it is a way of promotion made for the compensation of cost of free applications.'
• Furthermore, one of our moderators (Donna Buenaventura) who has since "passed" used to test software. She tested ASC and wrote under the Installation section:
'The installer of Advanced SystemCare is bundled with Yahoo! Toolbar We often see programs that are bundled with unwanted components - and, when they are bundled with security programs - this really saddens most members of the security community'.
Only as an added note, she wrote In Conclusion:
'Advanced SystemCare does not live up to its name and could, if used incautiously, cause more problems than it would fix. The automatic tasks that it performs are unacceptable because the program does not request permission from the user. The poor startup performance of the system is another point to note and to the program's suggestion that NOD32, WinPatrol and Outpost processes are questionable is another unacceptable aspect of Advanced SystemCare. Users who want this kind of system utlility would be well advised to look elsewhere.'
• Elsewhere, I found this:
What is spigot, inc - searchsettings.exe?:
Spigot, inc is a software company offering free extension applications for Mozilla Firefox browser called iObit Toolbar and Widgi Toolbar Platform. The extensions are considered malicious because it manipulated the browser to use Yahoo search even if the user is changing the search engines on manually to Google or Bing. Apart from that the Toolbar also provide dubious applications such as system scan and security scan options which serve for the benefits of iObit. Amazon and eBay search also included in the Toolbar'
• Without installing and testing it myself, the only (above) information I can trust and attest to is Donna's.
• As far as your present situation is concerned. Try what was first suggested. AdwCleaner.
Did you check your browser's extensions for signs of related items mentioned in your post? If it doesn't help, after cleaning all your temporary files, try the (FREE) Revo Uninstaller.
If you're presently redirected to unwanted sites give the following a try:
Hitman Pro - It's free to use without a license. If a virus is found, you will receive a free 30-day license to remove the threat. Note: There are separate downloads for 32 and 64-bit versions of Windows 7.
Kaspersky's TDSSKiller - Instructions are listed below. (Additional instructions can be found here)
Best of luck..