How to stop reporting irrelevant 404 errors in Search Console after recovering a hacked website?
JOHN MEULLER (Webmaster Analyst from Google):
This is something where, in general, you don’t really need to take action on these. It’s not something that we would see as a problem for crawling, indexing, or ranking, that a site has a lot of 404 errors. That’s essentially part of technical life on the web. Content comes. Content goes. It returns 404 for a really long time. We just check those URLs, because we think, maybe we’re missing something fantastic from this website. And we don’t want to ignore that just because it was a 404 in the past.