Not able to figure, by myself, if that was a coordinated atack

Greetings,

We had a virtual closed event planned to start on October, 2 at 5 PM (GMT-3) through October, 4.

There were 4.5k registered participants. It’s quite improbable that all of them would be present at 5PM that day.

There was 0.00% coming from Google (according to Analytics). That was expected, since it was a closed event and we made everything in our ability to keep it that way.

Then came The Spike… and the inauguration became a mess.

Since I’m not an expert on threats, I’'m wondering if you guys could help me diagnose it that was, actually, an attack.

TIA.

BTW, maybe this graph might help as well…

Yeah, it was most likely an attack. You don’t see that many challenges in any legitimate scenario.

Thanks @jnperamo!
Comforting to know that my suspicions have a basis.