It says what the malware does, it's a remote access toolkit... It gives control of your machine to the malware operator.
The malware operator could have done anything with that access... There's no way for the maintainers to know what was done on any given infected machine.
This is really scary for those who manage multiple things. I'm considering running a factory reset on everything from my router to my Steam Deck and remote server.
Announcements like this typically contain information that will help users identify if they were compromised, such as the name of files that are dropped or modified when the malware is initialized, startup entry names, etc. Obviously the person with remote access can get in and manually start doing things on individual machines, but that doesn't mean there aren't indicators present from the programmatic actions the malware took before that point or on machines that weren't manually accessed.