Process Injection: Ptrace System Calls (T1055.008)
Tactics: Stealth, Privilege Escalation · Platforms: Linux
The interactive view maps 1 detection strategy, 2 mitigations, 1 software entry to this technique, alongside D3FEND countermeasures and data-component coverage.
Sub-technique of Process Injection (T1055).
Overview
Adversaries may inject malicious code into processes via ptrace (process trace) system calls in order to evade process-based defenses as well as possibly elevate privileges. Ptrace system call injection is a method of executing arbitrary code in the address space of a separate live process.
Ptrace system call injection involves attaching to and modifying a running process. The ptrace system call enables a debugging process to observe and control another process (and each individual thread), including changing memory and register values. Ptrace system call injection is commonly performed by writing arbitrary code into a running process (ex: malloc) then invoking that memory with PTRACE_SETREGS to set the register containing the next instruction to execute. Ptrace system call injection can also be done with PTRACE_POKETEXT/PTRACE_POKEDATA, which copy data to a specific address in the target processes’ memory (ex: the current address of the next instruction).
Ptrace system call injection may not be possible targeting processes that are non-child processes and/or have higher-privileges.
Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via ptrace system call injection may also evade detection from security products since the execution is masked under a legitimate process.