nslookup is a command-line tool that can query the Domain Name System (DNS) and display information about domain names and IP addresses. The security analyst can use nslookup to find out the IP address of the malicious domain accountfix-office365.com that was used in the phishing attempt. This could help the analyst to block or trace the source of the attack. telnet, tracert, and curl are other command-line tools, but they are not as useful as nslookup for investigating a phishing attempt based on a domain name. Reference: https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/nslookup