For safety a more secure Browser...
Might try this, it's Chrome Browser without google & without Ads...
https://brave.com/
Flash should be removed...
Uninstall Flash Player for Mac OS (adobe.com)
To tell what else if anything...
We need to see what all is running, a report from this will not display any personal info...
EtreCheck is a FREE simple little diagnostic tool to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac. It will not display any personal info.
https://www.etrecheck.com/
Pastebin is a good place to paste the whole report if you capture the URL while there…
https://pastebin.com/
Whew, they've changed pastebin & made it harder, but after pasting in, click Create new paste button, then Embed button, then copy the URL...
<script src="https://pastebin.com/embed_js/KuvnghqA"></script>
The important part of the above is...
https://pastebin.com/embed_js/KuvnghqA
Workable but harder for me to work with...the Note tool on the bottom of this editor's toolbar, as shown in the image, to copy and paste the output from EtreCheck. In a Reply before you click post, look for this to add longer texts...