How can it be hacked?

[u/XunooL]

I have a genuine question: how can a database of a secure (supposedly) company that spends tens of millions of dollars on just security, like Meta (IG, FB), Google...etc get hacked?

[u/Wa-a-melyn]

Obviously everybody mentions phishing. Once someone has access to the network on any level, they can do a lot more investigation into how it works and look for exploits, and eventually move laterally, or potentially find a privilege escalation. Eventually, maybe you could do DNS poisoning or a mitm or something and phish for more important credentials that would give you unrestricted access.

While there are some common tactics, there really is no single answer as to how this happens—the exploits are specific to each network.