Most likely : Someone script kiddie tried to attack-it, and some user had a week password. There is tons of bot farm attacking any device connected to the internet all the time, as indiviual, we usually have a firewall/router between our PC and internet (so the whole family gets wifi), and keep all the "remote access services" off. But a telescope is typically the kind of infrastructure where "remote access" is necessary meaning that you're a target for attacker

Trisolarans.

A lot of these telescopes are on top of the tallest mountain around. Which in turn was probably pretty significant to whoever might have been dispossessed of the local area. So they can be surprisingly unpopular.

Like imagine if space aliens showed up, stole all the good land, killed loads of people, and then decided to build tools for their own notion of peaceful scientific exploration on top of Mount Everest, Mount Rushmore, and Half Dome.

Also, that Russian moon lander just crashed, so it could also be some kind of secret space cyber war of countries trying to make each other seem incompetent.

It could be a lot of things ranging from state threat actors looking for a toehold into a network or to cost the government time and resources or people doing it for the lulz.