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I conducted this week’s discussion board exercise using Radware’s Appwall firewall and Windows     Defender vulnerability scanner. I used version 7.5.7:94 of Appwall and kept a log of which ports were open before and after activating the firewall. Several ports were listed as open and listening while the Appwall firewall was running. Many ports were identified as active and listening but ports 135 and 123 were the most interesting. Remote Procedure Call (RPC) port 135 is used in client/server applications such as Exchange clients  (speedguide.net, 2018) . This port can be used for legitimate VPN connections but can also be used to malicious activity. TCP port 135 can be used to conduct denial of service (DoS) attacks, messenger popup attacks, and worm intrusions if not monitored and controlled  (speedguide.net, 2018) . UDP port 123 is the Network Time Protocol (NTP) port used for synchronizing time across networks.

There were several different ports open after running the scan without the Appwall firewall. FTP port 21 and TCP port 25 were both open and listening during this second scan. Port 21 is the file transport protocol (FTP) port and is used to establish connections with other clients for data sharing. This port is a popular target for malicious hackers as they can use it to inject Trojans into your end device. This port should always be monitored for authorized connections and activity because hackers can use your client without your knowledge through port 21. Port 25 is used for Simple Mail Transfer Protocol (SMTP). Many email services use port 25 to send out emails. Many Internet Service Providers (ISPs) block port 25 to prevent its customers from spamming others  (mediatemple.net, 2018) . This is why care must also be taken while monitoring this port because spammers can abuse it to send overwhelming amounts of spam emails to victims.

References

mediatemple.net. (2018, May 3). Checking your outgoing mail server (Is Port 25 blocked?) . Retrieved from mediatemple.net: https://mediatemple.net/community/products/dv/204404564/checking-your-outgoing-mail-server-(is-port-25-blocked)speedguide.net. (2018, May 3). Port 135 Denials. Retrieved from www.speedguide.net: https://www.speedguide.net/port.php?port=135