This detection rule identifies outbound ICMP packets exceeding 1,000 bytes that are sent to external IP addresses, indicating potential data exfiltration or command and control activities. By leveraging the Network_Traffic data model in Splunk, the rule filters out blocked packets and focuses on those that are allowed, which are significant in the context of cybersecurity threat detection. Given that threat actors often utilize ICMP for covert communications, monitoring such large packets can aid in revealing malicious behavior within the network. In essence, the detection serves as a critical mechanism to uncover potential threats while requiring proper implementation of the data model and clear understanding of the network's architecture for effective results.