An adversary may attempt to evade process tree-based analysis by modifying executed malware's parent process ID (PPID). If endpoint protection software leverages the “parent-child" relationship for detection, breaking this relationship could result in the adversary’s behavior not being associated with previous process tree activity. On Unix-based systems breaking this process tree is common practice for administrators to execute software using scripts and programs.(Citation: 3OHA double-fork 2022) On Linux systems, adversaries may execute a series of Native API calls to alter malware's process tree. For example, adversaries can execute their payload without any arguments, call the `fork()` API call twice, then have the parent process exit. This creates a grandchild process with no parent process that is immediately adopted by the `init` system process (PID 1), which successfully disconnects the execution of the adversary's payload from its previous process tree. Another example is using the “daemon” syscall to detach from the current parent process and run in the background.(Citation: Sandfly BPFDoor 2022)(Citation: Microsoft XorDdos Linux Stealth 2022)
Detects execution patterns where a child process is detached from its original parent, often showing up under 'launchd' (PID 1) with no parent lineage. These breakages in the process tree are indicative of evasive techniques using `daemon()`, `fork()` or background execution flags.
Detects anomalous process execution patterns where a process's parent terminates quickly after process creation or is re-parented to 'init' (PID 1), often indicating double-fork or daemon-style detachment. These behaviors sever the parent-child relationship and obscure the execution origin in process tree analysis.