https://blog.avast.com/join-the-incredible-avast-cyber-adventure-this-saturday-avast
I’d love to attend just need some plane tickets. 
I would have thought that this Cyber Adventure was virtual, given that it was only published by Vladislav Iliushin, on 14 June 2018. So two days wouldn’t allow much time to organise and travel to Prague.
Plus this:
Take on crypto-challenges, command injection, password cracking, machine learning, and more, all while you’re networking with the most passionate cybersecurity experts in the world.
But:
Breakfast and lunch will be provided, as well as snacks to keep you going through the adventure. Everyone who participates will receive a free gift, and Cyber Adventure winners will walk away with terrific prizes.Not to be missed is the after-party, where you can schmooze with other Cyber Adventurers as you enjoy barbecue and beer. There will even be a “fun zone” with amusing surprises.
So virtual food wouldn’t be very sustaining
If this truly is a Real World adventure, there isn’t much chance to attend unless you are relatively close to travel to Prague for the adventure.
It is, see: https://www.avast-adventure.com/
And I agree, announced way too late to attend.
I don’t doubt that, but for something ‘Cyber’ and talking of ‘networking’ you would think that this is an avenue they could explore.
It certainly doesn’t need you to arrange time off and transportation, all of which require time/planning.
I very often do Virtual, (Remote) conferences and they are quite effective. Next best thing to being there in person.
https://forum.avast.com/index.php?topic=78426.msg1457404#msg1457404