The script "Sissytease" is in Russian and it installs with the name intro.groovy

Not sure what was in the original intro file but it is lost now.

Can this script be deleted?

Yeah I'm having the same issue. Quite disturbing. I can't find the file location to delete it.
I think it should be taken down off the list of teases to be downloaded as it may be malicious.
My fault for downloading a tease that isn't validated.

I renamed it and republished it.