Custom PHP Website Security Expert Needed to Investigate & Remove Credit Card Skimming Malware

We are looking for an experienced Website Security Expert to urgently investigate and resolve a serious security breach on our live taxi booking website. Our website is a custom PHP application that uses Stripe for payment processing. We believe an attacker has gained unauthorised access to our website and injected malicious code into the payment page that attempts to steal customers' payment card information before it is processed by Stripe. In addition, an unauthorised administrator/user account has been created in our dashboard. This is a critical issue that requires immediate attention from someone with proven experience in incident response, malware removal, and securing production websites.