You can manually troubleshoot the issue by looking into associated probable causes
but that may take some time and great attention to detail. The methods suggested in
this site do not appear to require accessing command-line, though, so that's a plus...
http://www.thesafemac.com/eliminating-browser-redirects-and-advertisements/
•Tech Guides - the safe mac:
http://www.thesafemac.com/tech-guides/
{another and different browser issue relates to pop-up messages and hold-hostage warnings
such as the situation shown here: "a Browser Pop-up has Taken Over my Safari browser"...}
https://sites.google.com/site/appleclubfhs/support/advice-and-articles/browser-p opup-hijack-safari
The method of restarting Safari with extensions off, as suggested in the above, is often good
enough to regain control over Safari; then be able to make setting corrections before relaunch.
• If Safari is slow, stops responding, quits unexpectedly, or has other issues - Apple Support
• Stop pop-up ads and adware in Safari - Apple Support
The Adware situation may be in relation to some other component that was installed in the system
while browsing or choosing to install software from unsafe sites. Avoid bittorrent & 'free' software
as it usually may contain bad or corrupted files that can play havoc with your Mac & its software.
Several kinds of malware or adware related symptoms may be manually dealt with, given time...
The above suggestions, including earlier reply, should be somewhat helpful depending on cause.
Good luck in this matter! 🙂