{"id":"710bdbce-495d-491d-9a8f-7d0d88d2b41e","title":"Special File Creation via Mknod Syscall","description":"Detects usage of the `mknod` syscall to create special files (e.g., character or block devices).\nAttackers or malware might use `mknod` to create fake devices, interact with kernel interfaces,\nor establish covert channels in Linux systems.\nMonitoring the use of `mknod` is important because this syscall is rarely used by legitimate applications,\nand it can be abused to bypass file system restrictions or create backdoors.\n","author":"Milad Cheraghi","status":"experimental","level":"low","date":"2025-05-31","modified":"2025-12-05","tags":["attack.privilege-escalation","attack.persistence","attack.t1543.003"],"technique_ids":["T1543.003"],"logsource":{"product":"linux","service":"auditd"},"falsepositives":["Device creation by legitimate scripts or init systems (udevadm, MAKEDEV)","Container runtimes or security tools during initialization"],"references":["https://man7.org/linux/man-pages/man2/mknod.2.html","https://hopeness.medium.com/master-the-linux-mknod-command-a-comprehensive-guide-1c150a546aa8"],"source_path":"rules/linux/auditd/syscall/lnx_auditd_susp_special_file_creation_via_mknod_syscall.yml","source_sha256":"ed033360d0682c68bb8264a21570ec86d51dff40bf7ebb654615371e48ab7399","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/linux/auditd/syscall/lnx_auditd_susp_special_file_creation_via_mknod_syscall.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: Special File Creation via Mknod Syscall\nid: 710bdbce-495d-491d-9a8f-7d0d88d2b41e\nstatus: experimental\ndescription: |\n    Detects usage of the `mknod` syscall to create special files (e.g., character or block devices).\n    Attackers or malware might use `mknod` to create fake devices, interact with kernel interfaces,\n    or establish covert channels in Linux systems.\n    Monitoring the use of `mknod` is important because this syscall is rarely used by legitimate applications,\n    and it can be abused to bypass file system restrictions or create backdoors.\nreferences:\n    - https://man7.org/linux/man-pages/man2/mknod.2.html\n    - https://hopeness.medium.com/master-the-linux-mknod-command-a-comprehensive-guide-1c150a546aa8\nauthor: Milad Cheraghi\ndate: 2025-05-31\nmodified: 2025-12-05\ntags:\n    - attack.privilege-escalation\n    - attack.persistence\n    - attack.t1543.003\nlogsource:\n    product: linux\n    service: auditd\ndetection:\n    selection:\n        type: 'SYSCALL'\n        SYSCALL: 'mknod'\n    condition: selection\nfalsepositives:\n    - Device creation by legitimate scripts or init systems (udevadm, MAKEDEV)\n    - Container runtimes or security tools during initialization\nlevel: low\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1543.003","id":"T1543.003","name":"Windows Service","page":"techniques/enterprise/T1543.003/"}],"data_path":"data/detection-rules/710bdbce-495d-491d-9a8f-7d0d88d2b41e.json","kind":"sigma"}