Sigma rule: Potential Container Discovery Via Inodes Listing

Rule

Title

Potential Container Discovery Via Inodes Listing

Status

test

Level

low

Author

Seth Hanford

Date

2023-08-23

Modified

2025-11-24

File

rules/linux/process_creation/proc_creation_lnx_susp_inod_listing.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects listing of the inodes of the "/" directory to determine if the we are running inside of a container.

Log source

product

linux

category

process_creation

Detection

selection_ls_img:
    Image|endswith: '/ls'    # inode outside containers low, inside high
selection_ls_cli:
    - CommandLine|endswith: ' /'
    - CommandLine|contains: ' / '
selection_regex_inode:
    CommandLine|re: '(?:\s-[^-\s]{0,20}i|\s--inode\s)'      # -i finds inode number
selection_regex_dir:
    CommandLine|re: '(?:\s-[^-\s]{0,20}d|\s--directory\s)'  # -d gets directory itself, not contents
condition: all of selection_*

False positives (as the rule lists them)

• Legitimate system administrator usage of these commands
• Some container tools or deployments may use these techniques natively to determine how they proceed with execution, and will need to be filtered

Tags

• attack.discovery
• attack.t1082

MITRE ATT&CK ids this rule names

• T1082

References

• https://blog.skyplabs.net/posts/container-detection/
• https://stackoverflow.com/questions/20010199/how-to-determine-if-a-process-runs-inside-lxc-docker

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_inod_listing.yml