Final answer:
The initial step after finding open ports in a network port scan is to determine the reason for the ports being open. If unjustified, a vulnerability scan should be conducted to check for security flaws, followed by possibly reenabling the local host firewall to mitigate risks.
Step-by-step explanation:
Upon discovering open ports during a network port scan, the next action should be to determine the reason for the ports being open. This step is crucial as it helps in identifying whether the open ports are required for legitimate purposes or if they are a security risk. It involves checking documentation and configurations or speaking with system administrators to ascertain the necessity of these ports being accessible.
If the open ports are not required for business or operational purposes, or if their status cannot be justified, then it's essential to consider the workstation as potentially compromised. Following the initial investigation, running a vulnerability scan on the workstation can help in identifying vulnerable services that might be exploited by an attacker. This scan provides detailed information about the security flaws and assists in prioritizing their remediation.
Lastly, if it's determined that the workstation's open ports are not intentional and pose a security threat, reenabling the workstation's local host firewall and configuring proper firewall rules should be considered to prevent unauthorized access. Each action should be documented thoroughly to improve the overall security of the network infrastructure.