Which command line tool is used for viewing open ports and connections to detect trojans?

• A. Netstat
• B. Ping
• C. Tracert
• D. Nmap

Answer: (A)

Monitoring open ports and active connections helps you spot hidden backdoors that a trojan might use to communicate with an attacker. The command-line tool that directly provides this view is Netstat. It lists current network connections, listening ports, and the associated local and remote addresses, along with the connection state. With the right options, you can also see which process owns a given connection, making it easier to identify unfamiliar or suspicious activity on the host.

Ping is about reachability to a host, not the ports or ongoing connections. Tracert shows the path packets take to reach a host, not the local open ports or current connections. Nmap scans other machines to discover open ports and services on those hosts, which is great for network auditing, but it doesn’t reflect the live state of your own system’s ports and connections as Netstat does.