The following analytic identifies parent processes, browsers, Windows terminal applications, Office Products and Java spawning cmd.exe. By its very nature, many applications spawn cmd.exe natively or built into macros. Much of this will need to be tuned to further enhance the risk.
- Type: Anomaly
Product: Splunk Behavioral Analytics
- Last Updated: 2022-03-01
- Author: Ignacio Bermudez Corrales, Splunk
- ID: c10a18cb-fd80-4ffa-a844-25026e0a0c94
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 $main = from source | eval timestamp = time | eval metadata_uid = metadata.uid | eval process_pid = process.pid | eval process_file = process.file | eval process_file_path = process_file.path | eval process_file_name = lower(process_file.name) | eval process_cmd_line = lower(process.cmd_line) | eval actor_user = actor.user | eval actor_user_name = actor_user.name | eval actor_process = actor.process | eval actor_process_pid = actor_process.pid | eval actor_process_file = actor_process.file | eval actor_process_file_path = actor_process_file.path | eval actor_process_file_name = lower(actor_process_file.name) | eval device_hostname = device.hostname | where ((actor_process_file_name IN ("winword.exe", "excel.exe", "outlook.exe", "acrobat.exe", "acrord32.exe", "iexplore.exe", "opera.exe", "firefox.exe", "powershell.exe")) OR (actor_process_file_name="java.exe" AND (NOT match(actor_process_file_name, /(?i)patch1-Hotfix1a/)=true)) OR (actor_process_file_name="chrome.exe" AND (NOT process_cmd_line="chrome-extension"))) AND process_file_name="cmd.exe" --finding_report--
The SPL above uses the following Macros:
detect_prohibited_applications_spawning_cmd_exe_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
In order to successfully implement this analytic, you will need endpoint process data from a EDR product or Sysmon. This search has been modified to process raw sysmon data from attack_range's nxlogs on DSP.
Known False Positives
There are circumstances where an application may legitimately execute and interact with the Windows command-line interface.
Associated Analytic Story
|35.0||70||50||An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest_device_id$ by user $dest_user_id$, producing a suspicious event that warrants investigating.|
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: 5