Sigma rule: Process Execution From Shared Memory Directory

Rule

Title

Process Execution From Shared Memory Directory

Status

experimental

Level

high

Author

Stan Beukers

Date

2026-06-20

File

rules/linux/process_creation/proc_creation_lnx_susp_exec_from_dev_shm.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the execution of a binary from the Linux shared memory directory /dev/shm.
This directory is a tmpfs mount backed entirely by RAM and is abused by attackers for fileless malware staging because files written there never touch physical disk and may evade disk-based detection.

Log source

product

linux

category

process_creation

Detection

selection:
    Image|startswith: '/dev/shm/'
condition: selection

False positives (as the rule lists them)

• Unlikely in production environments; some container runtimes or IPC frameworks may use /dev/shm for inter-process communication but should not spawn executables.

Tags

• attack.stealth
• attack.execution
• attack.t1027.011

MITRE ATT&CK ids this rule names

• T1027.011

References

• https://www.sysdig.com/blog/containers-read-only-fileless-malware
• https://unfinished.bike/fun-with-the-new-bpfdoor-2023
• https://asiapacificdefencereporter.com/wp-content/uploads/2023/08/Final-CRWD-2023-Threat-Hunting-Report.pdf
• https://www.crowdstrike.com/en-us/blog/how-to-hunt-for-decisivearchitect-and-justforfun-implant/
• https://www.linkedin.com/posts/avradeep_malware-apt-infostealer-activity-7373203959697719296-JR-7
• https://www.stormshield.com/news/orbit-analysis-of-a-linux-dedicated-malware/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/linux/process_creation/proc_creation_lnx_susp_exec_from_dev_shm.yml