This search looks for events where
PsExec.exe is run with the
accepteula flag in the command line. PsExec is a built-in Windows utility that enables you to execute processes on other systems. It is fully interactive for console applications. This tool is widely used for launching interactive command prompts on remote systems. Threat actors leverage this extensively for executing code on compromised systems. If an attacker is running PsExec for the first time, they will be prompted to accept the end-user license agreement (EULA), which can be passed as the argument
accepteula within the command line.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2021-09-16
- Author: Bhavin Patel, Splunk
- ID: 27c3a83d-cada-47c6-9042-67baf19d2574
Kill Chain Phase
- Actions on Objectives
- CIS 8
1 2 3 4 5 6 | tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_psexec` Processes.process=*accepteula* by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `detect_psexec_with_accepteula_flag_filter`
The SPL above uses the following Macros:
detect_psexec_with_accepteula_flag_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Supported Add-on (TA)
List of Splunk Add-on’s tested to work with the analytic.
List of fields required to use this analytic.
How To Implement
To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the
Endpoint datamodel in the
Processes node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.
Known False Positives
Administrators can leverage PsExec for accessing remote systems and might pass
accepteula as an argument if they are running this tool for the first time. However, it is not likely that you'd see multiple occurrences of this event on a machine
Associated Analytic Story
- SamSam Ransomware
- DHS Report TA18-074A
- HAFNIUM Group
- DarkSide Ransomware
- Active Directory Lateral Movement
- CISA AA22-320A
|35.0||50||70||An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ running the utility for possibly the first time.|
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: 4