Red-Team Lab Demonstrates Open-Relay Phishing Risk with GoPhish

Summary

A red-team lab demonstrates how to identify SMTP servers, test for unauthenticated open relays and sender impersonation, then connect a relay to GoPhish. The speaker recommends checking internal and exposed mail servers.

Key points

• The presenter uses an Nmap scan for SMTP port 25 and DNS MX records to locate mail servers.
• In the lab, an intentionally unauthenticated mail relay accepts messages without SMTP credentials.
• The demonstration shows sending email with an impersonated sender address, including an administrator identity.
• The presenter configures a GoPhish SMTP sending profile and describes using templates, landing pages and target lists for phishing campaigns.
• The speaker advises testing both internal and externally exposed mail servers for unauthenticated sending and sender impersonation.
• For real-world operations, the presenter recommends custom-building and obfuscating GoPhish to make detection more difficult.