Detection rules › Splunk
Windows Shell or Script Execution From IIS Directory
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.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | T1190 Exploit Public-Facing Application |
| Persistence | T1505.004 Server Software Component: IIS Components |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
Rule body splunk
name: Windows Shell or Script Execution From IIS Directory
id: f058f7f9-d5cf-4a79-a720-24e93e87c8bf
version: 2
creation_date: '2021-09-02'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: Anomaly
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.
data_source:
- Sysmon EventID 1
- CrowdStrike ProcessRollup2
search: |-
| 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`
how_to_implement: 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.
drilldown_searches:
- earliest_offset: $info_min_time$
latest_offset: $info_max_time$
name: View the detection results for - "$user$" and "$dest$"
search: '%original_detection_search% | search user = "$user$" dest = "$dest$"'
- name: View risk events for the last 7 days for - "$user$" and "$dest$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset: 7d
latest_offset: "0"
intermediate_findings:
entities:
- field: dest
type: system
score: 50
message: Potential Suspicious Commands in IIS Directory activity observed on $dest$ via $process$.
threat_objects:
- field: parent_process_name
type: parent_process_name
analytic_story:
- ProxyShell
- ProxyNotShell
asset_type: Endpoint
mitre_attack_id:
- T1190
- T1505.004
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1190/snapattack/snapattack.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog
test_type: unit
Stages and Predicates
Stage 1: tstats
| 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
Stage 2: search
| `drop_dm_object_name(Processes)`
Stage 3: search
| `security_content_ctime(firstTime)`
Stage 4: search
| `security_content_ctime(lastTime)`
Stage 5: search
| `windows_shell_or_script_execution_from_iis_directory_filter`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Processes.parent_process_name | in |
|
Processes.process_current_directory | eq |
|