Trusted Mac apps could possibly be swapped out for malware

It takes a very specific series of steps and even then it cannot affect every Mac app, but researchers have found a way to bypass Apple's macOS security and run malware.
There is a way to get malware onto your Mac, although it's not very likely. Background skull and crossbones image by stg_max_gts
If they don't already come installed on the Mac, macOS apps are either downloaded from the Mac App Store, or from developers' websites. Whichever it is, macOS has security measures to prevent bad actor