Linux Change File Owner To Root
Description
This analytic looks for a commandline that change the file owner to root using chown utility tool. This technique is commonly abuse by adversaries, malware author and red teamers to escalate privilege to the targeted or compromised host by changing the owner of their malicious file to root. This event is not so common in corporate network except from the administrator doing normal task that needs high privilege.
- Type: Anomaly
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2021-12-21
- Author: Teoderick Contreras, Splunk
- ID: c1400ea2-6257-11ec-ad49-acde48001122
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
- DE.CM
CIS20
- CIS 3
- CIS 5
- CIS 16
CVE
Search
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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name = chown OR Processes.process = "*chown *") AND Processes.process = "* root *" by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.process_guid
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `linux_change_file_owner_to_root_filter`
Macros
The SPL above uses the following Macros:
linux_change_file_owner_to_root_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Required fields
List of fields required to use this analytic.
- _time
- Processes.dest
- Processes.user
- Processes.parent_process_name
- Processes.process_name
- Processes.process
- Processes.process_id
- Processes.parent_process_id
How To Implement
To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you can use the Add-on for Linux Sysmon from Splunkbase.
Known False Positives
Administrator or network operator can execute this command. Please update the filter macros to remove false positives.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
64.0 | 80 | 80 | A commandline $process$ that may change ownership to root on $dest$ |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
- https://unix.stackexchange.com/questions/101073/how-to-change-permissions-from-root-user-to-all-users
- https://askubuntu.com/questions/617850/changing-from-user-to-superuser
Test Dataset
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
source | version: 1