Update windows_powershell_process_with_malicious_string.yml

Author: nterl0k

detections/endpoint/windows_powershell_process_with_malicious_string.yml

@@ -52,21 +52,14 @@ rba:
 tags:
   analytic_story: 
   - Malicious PowerShell
-  asset_type: Endpoint
-  message: 
+  asset_type: Endpoint 
   mitre_attack_id: 
   - T1059
   - T1059.001
   product: 
   - Splunk Enterprise
   - Splunk Enterprise Security
   - Splunk Cloud
-  required_fields: 
-  - Processes.user 
-  - Processes.dest
-  - Processes.process_name 
-  - Processes.process
-  - Processes.parent_process_name
   security_domain: threat
 tests:
 - name: True Positive Test