From what i learn Ddos is literally spamming a server with a bunch of bot until their server is f--ked up. If a big website such as MD that uses cloudflare server that literally have a big server size can be Ddos-ed and affecting their server performance which can only be achieve if the cracker have already infect a lot of computer and uses that zombie computer to launch an attack
So tracking down ddos-er that can ddos a big website such as MD and it's affecting their system would be hard since they using SOCKS,etc,etc
These DDoS are purposely done by paid hackers from other manga site especially like mangafox and etc since those site have beef with previously batoto and now mangadex
Other theory
Big corporation are hunting illegal manga site and mangadex are one of top target after batoto fell
@ichi24 most likely the agregator site in my opinion.
Big corporation wouldn't do petty things like this since I don't think it'll benefit them anyway.
But agregator site, they'll benefits since they use ads on their site and of course if MangaDex got DDoS, the reader probably going to go to their (the agregator) sites.