I doubt it downloaded or executed anything, it probably just did a base64 decode using some tool and then analysed the decoded bash command which would be very easy. Seems like a good use of an LLM to me.
Out of curiosity I asked chatgpt what the malware does, but erased some parts of the base64 encoded string. It still gave the same answer as the blog. I take that as a strong indication that this script is in its training set.