Sigma is the open generic signature format for SIEM systems. Each rule below converts to native syntax for Splunk, Elastic, Sentinel, and other SIEMs. Expand any rule to see its raw YAML.
Potential Malicious Usage of CloudTrail System Manager
Detect when System Manager successfully executes commands against an instance.
status testauthor jamesc-grafanaid 38e7f511-3f74-41d4-836e-f57dfa18eead
view Sigma YAML
title: Potential Malicious Usage of CloudTrail System Manager
id: 38e7f511-3f74-41d4-836e-f57dfa18eead
status: test
description: |
Detect when System Manager successfully executes commands against an instance.
references:
- https://github.com/elastic/detection-rules/blob/v8.6.0/rules/integrations/aws/initial_access_via_system_manager.toml
author: jamesc-grafana
date: 2024-07-11
modified: 2025-12-08
tags:
- attack.privilege-escalation
- attack.initial-access
- attack.t1566
- attack.t1566.002
logsource:
product: aws
service: cloudtrail
detection:
selection_event:
eventName: 'SendCommand'
eventSource: 'ssm.amazonaws.com'
selection_status_success:
errorCode: 'Success'
selection_status_null:
errorCode: null
condition: selection_event and 1 of selection_status_*
falsepositives:
- There are legitimate uses of SSM to send commands to EC2 instances
- Legitimate users may have to use SSM to perform actions against machines in the Cloud to update or maintain them
level: high
medium
Suspicious Email Delivered In Microsoft 365
Detects instances where an email, identified as malicious or suspicious by the Microsoft Defender for Office 365 (formerly ATP) engine, was delivered to a user's Inbox or Junk folder.
It might indicate that a potential threat, such as a spearphishing attachment or links, has bypassed initial blocking mechanisms and reached an end-user, requiring further investigation and potential remediation.
status experimentalauthor Marco Pedrinazzi (@pedrinazziM) (InTheCyber)id 3569aefd-e535-4391-8c18-24bd01a21eaf
view Sigma YAML
title: Suspicious Email Delivered In Microsoft 365
id: 3569aefd-e535-4391-8c18-24bd01a21eaf
status: experimental
description: |
Detects instances where an email, identified as malicious or suspicious by the Microsoft Defender for Office 365 (formerly ATP) engine, was delivered to a user's Inbox or Junk folder.
It might indicate that a potential threat, such as a spearphishing attachment or links, has bypassed initial blocking mechanisms and reached an end-user, requiring further investigation and potential remediation.
references:
- https://learn.microsoft.com/en-us/defender-office-365/threat-explorer-real-time-detections-about
- https://research.splunk.com/cloud/605cc93a-70e4-4ee3-9a3d-1a62e8c9b6c2/
- https://github.com/Bert-JanP/Hunting-Queries-Detection-Rules/blob/e7250648cb16d4a497ae8737943bf010ea96d2e6/Defender%20For%20Cloud%20Apps/MaliciousEmailDeliveredInMailbox.md
author: Marco Pedrinazzi (@pedrinazziM) (InTheCyber)
date: 2026-01-27
tags:
- attack.initial-access
- attack.t1566.001
- attack.t1566.002
logsource:
service: audit
product: m365
detection:
selection:
Workload: 'ThreatIntelligence'
Operation: 'TIMailData'
Directionality: 'Inbound'
filter_main_blocked:
DeliveryAction: 'Blocked'
condition: selection and not 1 of filter_main_*
falsepositives:
- Unlikely
level: medium
medium
Suspicious Execution via macOS Script Editor
Detects when the macOS Script Editor utility spawns an unusual child process.
status testauthor Tim Rauch (rule), Elastic (idea)id 6e4dcdd1-e48b-42f7-b2d8-3b413fc58cb4