There's a lot of voodoo in that script, i can't easily tell it's safe by reading the code.
I'd expect some reaction/solution from official Arch developers...
All of the packages I have triaged involved the atomic-lockfile npm package, so this is something you could try:
npm cache ls | grep atomic-lockfile
The problem with an officially endorsed solution is that the rootkit authors could push an update that hides/removes the indicators of compromise the endorsed script checks for (e.g. it would be trivial to have the malware delete atomic-lockfile from the npm cache).Really conveys that sense of urgency + the stakes tied to a major malware attack like that.