Of course, one of the areas where we are most vulnerable for security on our Macs is through web browsers. As far as I can tell, most browser developers are making there software more and more secure. However, I do have a caution in the Safari browser for you.
In the Safari Web Browser Preferences make sure you are in the General Tab:
Now look at the last entry in the General Tab area, “Open safe files after downloading.” The default for Safari is to have that box checked so your macOS opens downloaded files automatically. That is convenient and all, but it is a huge security risk. You never know what you are downloading these days, it could be malware or just some other type of “badguyware”. So, I highly recommend unchecking this box. Your files will then download, but not open automatically. You can examine the files in your Downloads Folder to see if anything looks suspicious. By the way, if you do an update to Safari I believe it may turn that feature back on so check that setting after doing any Safari or macOS updates on your machine.
Google Chrome does not offer this auto open feature. Here is there Downloads settings:
There is nothing in their settings about auto opening downloaded files. A very secure posture to take.
The Firefox web browser is the same:
Firefox does not offer any auto opening features either.
Apple offers lots of little conveniences in their software. It is all about “ease of use”. However, sometimes it is just better to turn some of those “features” off for safety’s sake.