When you say...I've already tried 'Malware'.......do you mean Malwarebytes, because that would be my choice to remove anything left behind after clearing-out Knctr.
Knctr would have arrived in your equipment (as a packaged item) when you download a particular programme that you wanted. Consequently you will need to find and uninstall it and then give a run-through with the free edition of Malwarebytes.
Click Start > Control Panel > Uninstall a Program.
Look down list for Knctr and click onto it.
Click 'Uninstall' and then OK to save the changes.
Whilst in the 'Uninstall a Programme' section, it will be worthwhile noting the date that Knctr arrived and then seeing what else came as a download the same day; and removing any other downloads you you Do Not require.
Hans.