Detection rules › Splunk
System Processes Run From Unexpected Locations
The following analytic identifies system processes running from unexpected locations outside of paths such as C:\Windows\System32\ or C:\Windows\SysWOW64. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process paths, names, and hashes. This activity is significant as it may indicate a malicious process attempting to masquerade as a legitimate system process. If confirmed malicious, this behavior could allow an attacker to execute code, escalate privileges, or maintain persistence within the environment, posing a significant security risk.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | T1036.003 Masquerading: Rename Legitimate Utilities |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body splunk
name: System Processes Run From Unexpected Locations
id: a34aae96-ccf8-4aef-952c-3ea21444444d
version: 17
creation_date: '2019-10-16'
modification_date: '2026-05-13'
author: David Dorsey, Michael Haag, Nasreddine Bencherchali, Splunk
status: production
type: Anomaly
description: The following analytic identifies system processes running from unexpected locations outside of paths such as `C:\Windows\System32\` or `C:\Windows\SysWOW64`. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process paths, names, and hashes. This activity is significant as it may indicate a malicious process attempting to masquerade as a legitimate system process. If confirmed malicious, this behavior could allow an attacker to execute code, escalate privileges, or maintain persistence within the environment, posing a significant security risk.
data_source:
- Sysmon EventID 1
- Windows Event Log Security 4688
- CrowdStrike ProcessRollup2
search: |
| tstats `security_content_summariesonly`
count min(_time) as firstTime max(_time) as lastTime
FROM datamodel=Endpoint.Processes where
NOT Processes.process_path IN (
"*:\\$WINDOWS.~BT\\*",
"*:\\$WinREAgent\\*",
"*:\\Program Files \(x86\)\\Windows Kits\\10\\App Certification Kit\\*",
"*:\\Windows\\SoftwareDistribution\\*",
"*:\\Windows\\System32\\*",
"*:\\Windows\\SystemTemp\\*",
"*:\\Windows\\SysWOW64\\*",
"*:\\Windows\\uus\\*",
"*:\\Windows\\WinSxS\\*"
)
by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
Processes.parent_process_name Processes.parent_process_path Processes.process
Processes.process_exec Processes.process_guid Processes.process_hash
Processes.process_id Processes.process_integrity_level Processes.process_name
Processes.process_path Processes.user Processes.user_id Processes.vendor_product
| `drop_dm_object_name("Processes")`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| lookup update=true is_windows_system_file filename as process_name OUTPUT systemFile
| search systemFile=true
| `system_processes_run_from_unexpected_locations_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: This detection may require tuning based on third party applications utilizing native Windows binaries in non-standard paths.
references:
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1036.003/T1036.003.yaml
- https://attack.mitre.org/techniques/T1036/003/
drilldown_searches:
- name: View the detection results for - "$dest$"
search: '%original_detection_search% | search dest = "$dest$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$dest$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | 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: 20
message: A System process $process_name$ is running from $process_path$ on $dest$, potentially non-standard.
threat_objects:
- field: process_name
type: process_name
analytic_story:
- Suspicious Command-Line Executions
- Unusual Processes
- Ransomware
- Masquerading - Rename System Utilities
- Qakbot
- Windows Error Reporting Service Elevation of Privilege Vulnerability
- DarkGate Malware
asset_type: Endpoint
mitre_attack_id:
- T1036.003
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/T1036.003/atomic_red_team/windows-sysmon.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
NOT Processes.process_path IN (
"*:\\$WINDOWS.~BT\\*",
"*:\\$WinREAgent\\*",
"*:\\Program Files \(x86\)\\Windows Kits\\10\\App Certification Kit\\*",
"*:\\Windows\\SoftwareDistribution\\*",
"*:\\Windows\\System32\\*",
"*:\\Windows\\SystemTemp\\*",
"*:\\Windows\\SysWOW64\\*",
"*:\\Windows\\uus\\*",
"*:\\Windows\\WinSxS\\*"
)
by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
Processes.parent_process_name Processes.parent_process_path Processes.process
Processes.process_exec Processes.process_guid Processes.process_hash
Processes.process_id Processes.process_integrity_level Processes.process_name
Processes.process_path Processes.user Processes.user_id Processes.vendor_product
Stage 2: search
| `drop_dm_object_name("Processes")`
Stage 3: search
| `security_content_ctime(firstTime)`
Stage 4: search
| `security_content_ctime(lastTime)`
Stage 5: lookup
| lookup update=true is_windows_system_file filename as process_name OUTPUT systemFile
Stage 6: search
| search systemFile=true
Stage 7: search
| `system_processes_run_from_unexpected_locations_filter`
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
Processes.process_path | in | "*:\\$WINDOWS.~BT\\*", "*:\\$WinREAgent\\*", "*:\\Program Files \(x86\)\\Windows Kits\\10\\App Certification Kit\\*", "*:\\Windows\\SoftwareDistribution\\*", "*:\\Windows\\SysWOW64\\*", "*:\\Windows\\System32\\*", "*:\\Windows\\SystemTemp\\*", "*:\\Windows\\WinSxS\\*", "*:\\Windows\\uus\\*" |
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 |
|---|---|---|
systemFile | eq |
|