In the process of active service enumeration, a penetration tester identifies an SMTP daemon running on one of the target company’s servers. Which of the following actions would BEST enable the tester to perform phishing in a later stage of the assessment?
A. Test for RFC-defined protocol conformance.
B. Attempt to brute force authentication to the service.
C. Perform a reverse DNS query and match to the service banner.
D. Check for an open relay configuration.
