Windows Shell or Script Execution From IIS Directory
Description
Detects Windows command tools such as cmd, PowerShell, or pwsh being executed from the IIS installation directory. This can be indicative of exploitation of software reliant on IIS such as Exchange.
Query · spl
| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime
from datamodel=Endpoint.Processes where
Processes.process_current_directory="*:\\Windows\\System32\\inetsrv\\*"
Processes.parent_process_name IN (
"cmd.exe",
"powershell.exe",
"pwsh.exe"
)
by Processes.process Processes.vendor_product Processes.user_id Processes.process_hash
Processes.parent_process_name Processes.parent_process_exec Processes.action
Processes.dest Processes.process_current_directory Processes.process_path
Processes.process_integrity_level Processes.original_file_name Processes.parent_process
Processes.parent_process_path Processes.parent_process_guid Processes.parent_process_id
Processes.process_guid Processes.process_id Processes.user Processes.process_name
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_shell_or_script_execution_from_iis_directory_filter`
Implementation guide
The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
Known false positives
- Occasional administrative scripts or automated tasks might execute commands in the IIS directory. These instances are rare but should be verified before raising alerts.
Analyst notes
Known false positives: Occasional administrative scripts or automated tasks might execute commands in the IIS directory. These instances are rare but should be verified before raising alerts.