You can see in this log entry that the attempt is associated with WP Simple Pay, and contains other plugin relevant information:
Compared to a log entry from one of the other payment plugin attempts:
If the customer has other integrations, services, or websites using the same Stripe account, they’ll need to ensure they are up to date with Stripe’s best practices for blocking fraud and using similar techniques as WP Simple Pay offers: CAPTCHA, rate limiting, and email verification settings.
Customers should also review their Stripe API keys at https://dashboard.stripe.com/apikeys and revoke/roll any unused keys. Disconnecting from Stripe within WP Simple Pay and reconnecting will also regenerate the API keys.