It's not just the initial compromise that's getting "sophisticated hack" headlines in this case -- it's the extraordinary care that the attackers took to evade detection afterwards. Among other things: delaying communication to home base for a couple of weeks after the backdoor was initially installed; use of steganography to make that look like ordinary network traffic afterwards; use of entirely new exploits, not in any common database, to avoid detection triggered by a match.

The FireEye report describes all of this in more detail: https://www.fireeye.com/blog/threat-research/2020/12/evasive...