Title 18 Code 1030 says it is illegal to commit computer fraud but it is not a responsibility of your service provider to eat/pay for fraud committed against you.
Your only legal recourse under Title 18 Code 1030 is against the "violator". Amazon did not violate your computer systems and commit these offenses.
> Any person who suffers damage or loss by reason of a violation of this section may maintain a civil action against the violator to obtain compensatory damages and injunctive relief or other equitable relief.
On that basis, your contract stipulates who is responsible for fees associated with use of your AWS key by "any other third party".
> You are responsible for all applicable fees associated with use of the Services in connection with IAM, including fees incurred as a result of any User Credentials. You are responsible for maintaining the secrecy and security of the User Credentials (other than any key that we expressly permit you to use publicly). You are solely responsible, and we have no liability, for any activities that occur under the User Credentials, regardless of whether such activities are undertaken by you, your employees, agents, subcontractors or customers, or any other third party. You are responsible for the creation, distribution, and security (including enabling of access) of all User Credentials created under your AWS account, including credentials that you have used IAM to create or disclose to other parties.