# T1631.001_ptrace-system-calls

> 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.

- Skill: `cyberstrikeus/t1631-001-ptrace-system-calls` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/t1631-001-ptrace-system-calls`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/t1631-001-ptrace-system-calls/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/t1631-001-ptrace-system-calls

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# T1631.001 Ptrace System Calls

> **Sub-technique of:** T1631

## High-Level Description

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 (e.g., by using `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 process's memory (e.g., the current address of the next instruction).

Ptrace system call injection may not be possible when targeting processes with high-privileges, and on some systems those that are non-child processes.

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.

## Kill Chain Phase

- Defense Evasion (TA0030)
- Privilege Escalation (TA0029)

**Platforms:** Android, iOS

## What to Check

- [ ] Identify if Ptrace System Calls technique is applicable to target mobile environment
- [ ] Check Android devices for indicators of Ptrace System Calls
- [ ] Check iOS devices for indicators of Ptrace System Calls
- [ ] Assess detection coverage (1 detection strategies)

## How to Test

### Identify Attack Surface

Determine if the target mobile environment is susceptible to Ptrace System Calls by examining the target platforms (Android, iOS).

### Assess Existing Defenses

Review whether mitigations for T1631.001 are in place. If defenses are absent or misconfigured, this technique may be exploitable.

## Remediation Guide

No specific mitigations documented for this technique.

## Detection

### Detection of Ptrace System Calls

## Risk Assessment

| Finding                                  | Severity | Impact          |
| ---------------------------------------- | -------- | --------------- |
| Ptrace System Calls technique applicable | High     | Defense Evasion |

## CWE Categories

| CWE ID  | Title                        |
| ------- | ---------------------------- |
| CWE-693 | Protection Mechanism Failure |

## References

- [BH Linux Inject](https://github.com/gaffe23/linux-inject/blob/master/slides_BHArsenal2015.pdf)
- [Medium Ptrace JUL 2018](https://medium.com/@jain.sm/code-injection-in-running-process-using-ptrace-d3ea7191a4be)
- [PTRACE man](http://man7.org/linux/man-pages/man2/ptrace.2.html)
- [MITRE ATT&CK Mobile - T1631.001](https://attack.mitre.org/techniques/T1631/001)