Detect Proc Memory in Elastic Security
Adversaries may inject malicious code into processes via the /proc filesystem in order to evade process-based defenses as well as possibly elevate privileges. Proc memory injection involves enumerating the memory of a process via the /proc filesystem (/proc/[pid]) then crafting a return-oriented programming (ROP) payload with available gadgets/instructions. Each running process has its own directory, which includes memory mappings. Proc memory injection is commonly performed by overwriting the target processes' stack using memory mappings provided by the /proc filesystem. This information can be used to enumerate offsets (including the stack) and gadgets otherwise hidden by ASLR. Once enumerated, the target processes' memory map within /proc/[pid]/maps can be overwritten using dd.
MITRE ATT&CK
- Technique
- T1055 Process Injection
- Sub-technique
- T1055.009 Proc Memory
- Canonical reference
- https://attack.mitre.org/techniques/T1055/009/
Elastic Detection Query
file where event.action in ("open", "opened-file", "read") and file.path : "/proc/*/mem" or file.path : "/proc/*/maps" or file.path : "/proc/*/syscall" and not file.path : "/proc/self/*" and not process.name in ("ps", "top", "htop", "gdb", "strace", "ltrace", "perf", "systemd", "dockerd", "containerd", "lsof")Detects access to /proc/[pid]/mem or /proc/[pid]/maps by processes other than known legitimate debuggers and system tools. These paths are used in proc memory injection (T1055.009) to enumerate memory layout and directly overwrite process memory via dd or similar utilities.
Data Sources
Required Tables
False Positives & Tuning
- Security scanning tools such as rkhunter or chkrootkit that enumerate /proc entries for legitimate integrity checks
- Custom application performance monitoring (APM) agents that read /proc/[pid]/maps to resolve symbols for profiling
- Container runtimes (containerd, dockerd) during process isolation checks — add their executable paths to the exclusion list after baseline review
Other platforms for T1055.009
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Read Target Process Memory Maps
Expected signal: auditd: open() syscall on /proc/<pid>/maps with the calling process (shell) details. The maps output shows memory regions including stack address needed for injection.
- Test 2DD-based /proc/pid/mem Write Simulation
Expected signal: auditd: open() on /proc/<pid>/maps. In a real injection: write() syscall to /proc/<pid>/mem would be logged. The dd command itself generates process creation events.
- Test 3Check /proc Hardening Configuration
Expected signal: No security telemetry — this is a configuration check. The output shows current hardening level.
References (5)
- https://attack.mitre.org/techniques/T1055/009/
- http://hick.org/code/skape/papers/needle.txt
- https://blog.gdssecurity.com/labs/2017/9/5/linux-based-inter-process-code-injection-without-ptrace2.html
- http://man7.org/linux/man-pages/man1/dd.1.html
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1055.009/T1055.009.md
Unlock Pro Content
Get the full detection package for T1055.009 including response playbook, investigation guide, and atomic red team tests.