Detect Proc Memory in CrowdStrike LogScale
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/
LogScale Detection Query
#event_simpleName = ProcessRollup2
| CommandLine = /\/proc\/[0-9]+\/(mem|maps|syscall)/
| ImageFileName != /(gdb|strace|ltrace|perf|systemd|dockerd|containerd|ps|top|htop|lsof)(\s|$)/
| regex(field=CommandLine, regex="/proc/(?P<target_pid>[0-9]+)/(?P<access_type>mem|maps|syscall)", flags=i)
| access_risk := if(access_type == "mem", "HIGH - Direct memory write via /proc/pid/mem", "MEDIUM - Memory layout recon via /proc/pid/maps")
| select([timestamp, ComputerName, UserName, ImageFileName, CommandLine, target_pid, access_type, access_risk])
| sort(timestamp, order=desc)CrowdStrike LogScale (Falcon) query using ProcessRollup2 events to identify process command lines referencing /proc/[pid]/mem or /proc/[pid]/maps. This detects adversaries invoking dd, Python, or custom ELF binaries that reference /proc paths in their command line arguments as part of ROP payload injection or memory layout reconnaissance. Excludes known legitimate debugging and monitoring tools.
Data Sources
Required Tables
False Positives & Tuning
- Custom shell scripts or Python utilities used by SRE teams to diagnose memory leaks by reading /proc/[pid]/maps and correlating with application heap dumps
- Forensic imaging tools (e.g. LiME loader scripts, custom memory acquisition utilities) legitimately used during incident response that reference /proc/pid/mem for volatile memory capture
- LD_PRELOAD-based instrumentation frameworks that read /proc/[pid]/maps at library injection time to resolve ASLR offsets for hooking — common in security research and legitimate APM products
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
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