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splunk-security_content/detections/endpoint/linux_sudoers_tmp_file_creation.yml
2024-06-26 14:41:53 +00:00

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2.6 KiB
YAML

name: Linux Sudoers Tmp File Creation
id: be254a5c-63e7-11ec-89da-acde48001122
version: 2
date: '2024-05-19'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects the creation of the "sudoers.tmp" file,
which occurs when editing the /etc/sudoers file using visudo or another editor on
a Linux platform. This detection leverages filesystem data to identify the presence
of "sudoers.tmp" files. Monitoring this activity is crucial as adversaries may exploit
it to gain elevated privileges on a compromised host. If confirmed malicious, this
activity could allow attackers to modify sudoers configurations, potentially granting
them unauthorized access to execute commands as other users, including root, thereby
compromising the system's security.
data_source:
- Sysmon for Linux EventID 11
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_path IN ("*sudoers.tmp*")
by Filesystem.dest Filesystem.file_name Filesystem.process_guid Filesystem.file_path
| `drop_dm_object_name(Filesystem)` | `security_content_ctime(lastTime)` | `security_content_ctime(firstTime)`
| `linux_sudoers_tmp_file_creation_filter`'
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.
references:
- https://forum.ubuntuusers.de/topic/sudo-visudo-gibt-etc-sudoers-tmp/
tags:
analytic_story:
- Linux Privilege Escalation
- Linux Persistence Techniques
asset_type: Endpoint
confidence: 90
impact: 80
message: A file $file_name$ is created in $file_path$ on $dest$
mitre_attack_id:
- T1548.003
- T1548
observable:
- name: dest
type: Hostname
role:
- Victim
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
required_fields:
- _time
- Filesystem.dest
- Filesystem.file_create_time
- Filesystem.file_name
- Filesystem.process_guid
- Filesystem.file_path
risk_score: 72
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data:
https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548.003/sudoers_temp/sysmon_linux.log
source: Syslog:Linux-Sysmon/Operational
sourcetype: sysmon:linux