Adversaries can provide malicious content to an XPC service daemon for local code execution. macOS uses XPC services for basic inter-process communication between various processes, such as between the XPC Service daemon and third-party application privileged helper tools. Applications can send messages to the XPC Service daemon, which runs as root, using the low-level XPC Service <code>C API</code> or the high level <code>NSXPCConnection API</code> in order to handle tasks that require elevated privileges (such as network connections). Applications are responsible for providing the protocol definition which serves as a blueprint of the XPC services. Developers typically use XPC Services to provide applications stability and privilege separation between the application client and the daemon.(Citation: creatingXPCservices)(Citation: Designing Daemons Apple Dev) Adversaries can abuse XPC services to execute malicious content. Requests for malicious execution can be passed through the application's XPC Services handler.(Citation: CVMServer Vuln)(Citation: Learn XPC Exploitation) This may also include identifying and abusing improper XPC client validation and/or poor sanitization of input parameters to conduct Exploitation for Privilege Escalation.
Detects anomalous use of macOS XPC services for code execution. Monitors for processes invoking privileged XPC daemons with abnormal parameters, unexpected binaries communicating over NSXPCConnection, or helper tools executing code outside of their expected parent process lineage. Correlates process access attempts to system-level daemons, privilege escalations via XPC misconfigurations, and injection of malicious payloads through inter-process communication.