How can a lamp on the laptop flash when it is neither on, nor has the battery or is just charged?

The title refers to my battery indicator. Can anyone explain that?

Just because, according to Windows, it has no remaining capacity, it is not really empty, there's still a lot of residual voltage, a completely empty battery could no longer be charged

So isn't it because I was hacked or because of a virus?

Of course not. How should a virus be active when the computer is off? And why should he let a lamp shine?

I already told him, but he probably doesn't believe me.

Presumably the newspapers are full of reports about the internet mafia flashing lights ;-)