Did you, or perhaps someone in your family, or perhaps someone who recently had access to your computer order an e-book subscription?
If the answer to all the above is 'no' then you know that the charge to your account is a scam, and you treat it like you treat any other phony charge to your account: call the card issuer and get it reversed.
As a result of all the security breaches you read about, your and my and just about everybody else's information is widely available on the dark web (like the 'dark side.') Scammers will try their luck to see if they can get away with something. As soon as you report the phony charge to the card issuer, it's game over for the scammer.