possible malware/adware

Download and run the free version of Malwarebytes to remove any suspected malware/adware. It was developed by a long time contributor to these forums and a highly respected member of the computer security community. 

If you're still having problems download and run Etrecheck. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support  to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

Copy the report

and use the Add Text button to include the report in your reply. How to use the Add Text Feature When Posting Large Amounts of Text, i.e. an Etrecheck Report

IMPORTANT:

Before running Etrecheck assign Full Disk Access to Etrecheck in the Etrecheck's Privacy preference pane so that it can get additional information from the Console and log files for the report:

Also click and read the About info to further permit full disk access.

Then we can examine the report and see if we can determine what might be causing the problem.

If you suspect you have installed adware/malware:

>System Preferences>Profiles. found next to Accessibility (click into it and then remove all the suspicious things from the list.)

This Preference pane may not be present if no profiles found.

Adware Removal Guide—Manual removal of : http://www.thesafemac.com/arg-identification/

or

Try running this trusted utility https://www.malwarebytes.com/mac/

also Verify you are not using SOCKS proxy:

>System Preferences>Networks>Advanced>Proxy uncheck the box

Adware/malware launch daemons can set SOCKS proxies without user participation.

(SOCKS is an Internet protocol that exchanges network packets between a client and server through a proxy server.)