This analytic looks for suspicious command-lines that can be possibly used to modify user profile files to automatically execute scripts/executables by shell upon reboot of the machine. This technique is commonly abused by adversaries, malware and red teamers as persistence mechanism to the targeted or compromised host. This Anomaly detection is a good indicator that someone wants to run code after reboot which can be done also by the administrator or network operator for automation purposes.
- Type: Anomaly
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2021-12-20
- Author: Teoderick Contreras, Splunk
- ID: 9c94732a-61af-11ec-91e3-acde48001122
Kill Chain Phase
- CIS 3
- CIS 5
- CIS 16
1 2 3 4 5 6 | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process = "*echo*" AND Processes.process IN("*~/.bashrc", "*~/.bash_profile", "*/etc/profile", "~/.bash_login", "*~/.profile", "~/.bash_logout") 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_possible_append_command_to_profile_config_file_filter`
The SPL above uses the following Macros:
linux_possible_append_command_to_profile_config_file_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
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 use this commandline for automation purposes. Please update the filter macros to remove false positives.
Associated Analytic story
|49.0||70||70||a commandline $process$ that may modify profile files in $dest$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 1