I am sorry to be alarmist, but stop using Chrome on macOS 10.13 High Sierra or 10.14 Mojave. [EDIT: This includes outdated versions of Brave, Microsoft Edge, Opera, Vivaldi and pretty much any Chromium-based browser. (ARC only supports macOS 12 Monterey or higher).]
Even if you have the final version of Google Chrome for macOS 10.13 or 10.14 ( 116.0.5845.187 ), it only fixes the WebP issue, but does not fix the critical WebM vulnerability. I posted about this in another discussion. Moving forward, there are already a growing number of High severity issues (that we know of) and will be more as time goes on. It is unwise to continue using non-current browsers on the open internet. This includes Safari.
Export your Chrome bookmarks and write down any important login info so you can use them in another browser. After that, trash the Chrome app (from Applications) and just leave it in your Trash for a while in case you need to restore it and get some missing information.
For now you can use Firefox 115 ESR and get security updates “until September 2024”.
After install, make sure Firefox (ESR) is your default browser (System Prefs > General > Default web browser). Additionally, I would manually block Safari in the firewall (Sys Prefs > Security > Firewall > Firewall Options… > [+] > Safari app) and uncheck the two “Automatically allow…” options in that same panel.
One other important thing is to check your Apple malware utilities are up to date. It is surprising the number of Macs that are not completing these “automatic” background checks with Apple in recent years. Howard Oakley’s SilentKnight is an excellent tool for this. It simply checks your versions against the current list, and if needed, lets you manually start the update/install from Apple’s servers. Be sure to re-check after any SilentKnight installation to make sure it succeeded. Ignore the firmware alert under your Mac model as that can only be updated with newer macOS versions.
These are the minimum actions I would suggest, but combined with a cautious approach to what you click on it should keep you going for a while.
[EDIT: Changed 1st paragraph to clarify macOS versions and Chromium variants.]