I have had about 10 days ago this problem and formatted my computer. It fixed, but then it returned yesterday (see screenshot) and I am not even sure where I got that. Chrome (not sure about Edge or Internet Explorer) randomly reroutes to this ads.1seven9.com website (which has the title "Your page is loading...") and then again to some ad website.
Windows Defender didn't find anything.
Malware Bytes didn't find anything.
Rkill didn't find anything
Farbar Recovery Scan Tool also (apparently) didn't find anything.
Adwcleaner didn't find anything.
Junkware Removal Tool also didn't find anything.
Zemana found a shortcut in the Start Menu to MegaSync tool, which I use for cloud that Zemana said contained "Malware:Win32/Startup-Gen.A!Neng". I quarantined it for safety, then I started MegaSync again and re-enabled "start with Windows" option, and once again Zemana points that file to me. Thus, I don't consider this to be the source of the problem.
Now I'm running Microsoft Malicious Software Removal Tool to see if I get anything.
2017.10.22-11.44.13-i0-t92-d1.txt
2017.10.22-11.55.12-i0-t92-d0.txt
Addition_22-10-2017 11.06.24.txt
Addition_22-10-2017 11.13.26.txt
AdwCleaner[S0].txt
FRST_22-10-2017 11.06.24.txt
FRST_22-10-2017 11.13.26.txt
JRT.txt
MalwereBytes.txt
Rkill.txt
Shortcut_22-10-2017 11.13.26.txt