Query: detect Detects instances where an email, identified as malicious or suspicious by the Microsoft Defender for Office 365 (former in logs
Matching passage: Sigma rule: Detects instances where an email, identified as malicious or suspicious by the Microsoft Defender for Office 365 (former. Logsource: m365 / audit. Rule: 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
Near-miss passage: Sigma rule: Monitor the creation of a new key under 'TaskCache' when a new scheduled task is registered by a process that is not svc. Logsource: windows / registry_set. Rule: title: Scheduled TaskCache Change by Uncommon Program id: 4720b7df-40c3-48fd-bbdf-fd4b3c464f0d status: test description: Monitor the creation of a new key under 'TaskCache' when a new scheduled task is registered by a process that is not svchost.exe, which is suspicious references: - https://thedfirreport.com/2021/03/29/sodinokibi-aka-revil-ransomware/ - https://labs.f-secure.com/blog/scheduled-task-tampering/ author: Syed Hasan (@syedhasan009) date: 2021-06-18 modified: 2025-10-22 tags: - attack.privilege-escalation - attack.execution - attack.persistence - attack.t1053 - attack.t1053.005 logsource: category: registry_set product: windows detection: selection: TargetObject|contains: SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\ filter_main_empty: Details: (Empty) filter_main_null: Details: null filter_main_other: TargetObject|contains: - Microsoft\Windows\UpdateOrchestrator - Microsoft\Windows\SoftwareProtectionPlatform\SvcRestartTask\Index - Microsoft\Windows\Flighting\OneSettings\RefreshCache\Index filter_main_mousocoreworker: Image|endswith: C:\Windows\System32\MoUsoCoreWorker.exe filter_main_services: Image|endswith: C:\Windows\System32\services.exe filter_main_tiworker: Image|startswith: C:\Windows\ Image|endswith: \TiWorker.exe filter_main_svchost: Image: C:\WINDOWS\system32\svchost.exe filter_main_ngen: Image|startswith: C:\Windows\Microsoft.NET\Framework Image|endswith: \ngen.exe TargetObject|contains: - \Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tasks\{B66B135D-DA06-4FC4-95F8-7458E1D10129} - \Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\Microsoft\Windows\.NET Framework\.NET Framework NGEN filter_main_office: Image: - C:\Program Files\Microsoft Office\root\Integration\Integrator.exe - C:\Program Files (x86)\Microsoft Office\root\Integration\Integrator.exe - C:\Program Files\Common Files\microsoft shared\ClickToRun\OfficeC2RClient.exe - C:\Program Files (x86)\Common Files\microsoft shared\ClickToRun\OfficeC2RClient.exe filter_main_msiexec: Image: C:\Windows\System32\msiexec.exe filter_main_explorer: Image: C:\Windows\explorer.exe TargetObject|contains: \Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\Microsoft\Windows\PLA\Server Manager Performance Monitor\ filter_main_system: Image: System filter_main_runtimebroker: Image: C:\Windows\System32\RuntimeBroker.exe filter_optional_dropbox_updater: Image: - C:\Program Files (x86)\Dropbox\Update\DropboxUpdate.exe - C:\Program Files\Dropbox\Update