This detection rule identifies potential IPSEC NAT Traversal traffic, which may indicate unauthorized attempts to establish encrypted communications over a NAT (Network Address Translation) environment. The rule monitors UDP traffic directed at port 4500, as this port is typically used for encapsulating IPSEC packets in NAT Traversal scenarios. While NAT Traversal is necessary for legitimate VPN traffic, threat actors may exploit this technology to camouflage their activities to bypass security measures. Administrators are advised to investigate detected instances of traffic on this port, assess legitimacy by reviewing traffic patterns, and distinguish between actual intrusion attempts and benign IPSEC traffic from known and trusted sources. Recommendations include examining the source and destination IPs involved in the traffic, correlating with other network behaviors, and implementing whitelisting for known legitimate IPSEC usage to minimize false positives.