Sending 100,000 spam mails in five minutes is difficult. This should be much more simple if you really want to do it.

A plausible motivation could be to keep the people that matters distracted and paralyzed to react while you blow an huge damm and create the second worst environmental disaster since Chernobyl in a well known country, casually in the same f*ing day

But I'm just speculating. All possible options are open at this point except thinking that this is normal. I assume that plagues also helped.