Abnormal Process ID or Lock File Created
Identifies the creation of a Process ID (PID), lock or reboot file created in temporary file storage paradigm (tmpfs) directory /var/run. On Linux, the PID files typically hold the process ID to track previous copies…
Description
Identifies the creation of a Process ID (PID), lock or reboot file created in temporary file storage paradigm (tmpfs) directory /var/run. On Linux, the PID files typically hold the process ID to track previous copies running and manage other tasks. Certain Linux malware use the /var/run directory for holding data, executables and other tasks, disguising itself or these files as legitimate PID files.
Detection logic
Its licence does not clear it for publishing here
Sunturai publishes a detection's own text where the licence it arrived under has been reviewed and permits it, and Elastic License 2.0 has not. The query as its source wrote it, its canonical form and the hash that pins this revision are in the workspace record.
Detection requirements
- Platform
- ContainersESXiLinuxmacOSWindows
The rule states no platform. This is derived from the 2 ATT&CK techniques it maps to.
- Log source category
- event_index
Known benign triggers
- False-Positives (FP) can appear if the PID file is legitimate and holding a process ID as intended. To differentiate, if the PID file is an executable or larger than 10 bytes, it should be ruled suspicious.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| exatrack.com/public/Tricephalic_Hellkeeper.pdf | 3 |
| twitter.com/GossiTheDog/status/1522964028284411907 | 5from 2 sources |
| www.elastic.co/security-labs/a-peek-behind-the-bpfdoor | 5from 2 sources |
| www.sandflysecurity.com/blog/linux-file-masquerading-and-malicious-pids-sandfly-1-2-6-update/ | 3 |
From the source
- At source
- Open at source
- Upstream identifier
- cac91072-d165-11ec-a764-f661ea17fbce
- Tagged by the source as
- Data Source: Elastic DefendData Source: Elastic EndgameDomain: EndpointNoise: HighOS: LinuxPerformance: NormalPlatform: LinuxProfile: AggressiveResources: Investigation GuideRule Type: New TermsTactic: ExecutionThreat: BPFDoorUse Case: Threat Detection
Licence
- Published under
- Elastic License 2.0Read the licence
- Attribution
- Required
Authorship
- Written by
- Published
- Sep 20, 2026
- Version
- 3