I have website being monitored by Google Analytics. One of the most visited pages is    /?from=http://www.traffic2cash.xyz/What does it mean? Somebody tried to inject some malware (...) into the website or something similar? It happened maybe only during 3 days in month so it should be not big deal, but I still better ask.
Most visited Page in Google Analytics - Malware?
google analytics
This is what's called ghost referral spam. They didn't actually visit your website but rather they used Google Analytics' Measurement Protocol API to send hits to your UA property. There's nothing you can do about this and it's a known issue with Google Analytics.