Just going to remind you all that https://canarytokens.org/ exists.
There are ways to try to prevent this from happening in a first place. I wrote kow (keys-on-the-wire) to fix this. Apps only see placeholder tokens. The proxy injects real key from the vault into outbound requests for allowed hosts.
Author here. Apache-2.0. [1] https://keysonthewire.com [2] https://github.com/inflightsec/keys-on-the-wire
It's not a guaranteed you'll know you've been hacked, but it's still quite a flag to leave. And there are services doing the equivalent of what you posted, but for cryptocurrencies: they contact you through email, SMS, snail mail even, if they detect that "coins at address ..." ever move.