Malware programs often modify the browser shortcut to force you attend numerous intrusive websites, show you ads and install additional adware on your PC. The problem is that antivirus programs and anti-malware utilities are able to kill malware but they often are unable to detect modified shortcuts and remove files which they are pointing to. As a result your browser can still direct you to a hijacking-webpage despite your computer is actually clean of malware. In this case you need to fix the shortcuts for your Chrome, Mozilla Firefox and other browsers manually.
Chrome has detected unusual behavior
Read our tips on what to do if you see a notification in Google Chrome like this:
Chrome has detected unusual behavior Is Chrome crashing, showing unusual startup pages, toolbars, or unexpected ads you can't get rid of... Run Chrome Cleanup Tool