Safari opens random websites

You have adware installed. 

Run EtreCheck again.

In the Sidebar, click the Security button.

 Locate  and remove entries under  Adware and Unsigned files.

 Click the “Remove” button.

You can also try Malwarebytes. Try downloading this program which was written by Thomas R, a long time poster. The program will search for malware/adware. The program will do the work for you which makes it easy. It may be necessary to run more than one scan. After running the scans, restart the computer.

Malwarebytes Anti-Malware for Mac      10.10 and later.       

Web site for download   https://www.malwarebytes.com

Malwarebytes uninstall.   

Malwarebytes for IOS.   

      Download EtreCheck, run it to see if there is any adware installed or not.

      https://etrecheck.com

      Click  “Free download” button,

      Open Downloads folder, click on it to open, and then select ”Open”.

      “Choose a problem” from the popup menu box, and then “Start EtreCheck” in the dialog.

      Click “Share Report” button in the toolbar, select “Copy report” .

      Paste the report when you reply.

      Note: This is a diagnostic test.