An International E-Commerce Company Has Identified Attack Traffic Originating from a Whitelisted

Multiple Choice

An international e-commerce company has identified attack traffic originating from a whitelisted third party's IP address used to mask the third party's internal network. The security team needs to block the attack traffic without impacting the vendor's services. Which of the following is the BEST approach to identify the threat?

A) Ask the third-party vendor to block the attack traffic
B) Configure the third party's proxy to begin sending X-Forwarded-For headers
C) Configure the e-commerce company's IPS to inspect HTTP traffic
D) Perform a vulnerability scan against the network perimeter and remediate any issues identified