The 'Log4Shell JNDI Payload Injection with Outbound Connection' detection rule identifies and responds to incidents related to the Log4Shell vulnerability (CVE-2021-44228), which affects Java web applications utilizing log4j. This rule continuously monitors web logs, specifically focusing on LDAP payload injections that exploit this vulnerability, indicated by patterns such as `${jndi:ldap://PAYLOAD_INJECTED}`. The detection leverages both the Web and Network_Traffic data models in Splunk, cross-referencing detected JNDI payloads with network communications directed at known malicious IP addresses. This combination of log analysis and network monitoring enables the identification of potentially malicious activities that could lead to remote code execution, unauthorized data access, and exploitation of compromised systems. Given the nature of the vulnerability, proactive monitoring is essential for organizations utilizing Java-based applications, enabling timely response to mitigate security risks associated with this exploit.