Why did AWS place and reverse a $1 charge on my card?

Some people receive these checks periodically, even when they aren’t actively using their account. If the transaction doesn’t disappear after a few days, appears for more than $1, or you notice unfamiliar activity, review your AWS billing and account activity and contact AWS account support or your card issuer.

That’s usually a temporary authorization hold used to verify that the payment method is valid. The charge and reversal can appear as separate $1 transactions, and the hold is normally released automatically. It doesn’t necessarily indicate that your card was compromised.