Sigma Rule Library

PST Export Alert Using New-ComplianceSearchAction

Alert when a user has performed an export to a search using 'New-ComplianceSearchAction' with the '-Export' flag. This detection will detect PST export even if the 'eDiscovery search or exported' alert is disabled in the O365.This rule will apply to ExchangePowerShell usage and from the cloud.

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Detection logic

selection

eventSource: SecurityComplianceCenter
Payload|contains|all:
  - New-ComplianceSearchAction
  - Export
  - pst

Condition

selection

Raw YAML

title: PST Export Alert Using New-ComplianceSearchAction
id: 6897cd82-6664-11ed-9022-0242ac120002
related:
    - id: 18b88d08-d73e-4f21-bc25-4b9892a4fdd0
      type: similar
status: test
description: Alert when a user has performed an export to a search using 'New-ComplianceSearchAction' with the '-Export' flag. This detection will detect PST export even if the 'eDiscovery search or exported' alert is disabled in the O365.This rule will apply to ExchangePowerShell usage and from the cloud.
references:
    - https://learn.microsoft.com/en-us/powershell/module/exchange/new-compliancesearchaction?view=exchange-ps
author: Nikita Khalimonenkov
date: 2022-11-17
tags:
    - attack.collection
    - attack.t1114
logsource:
    service: threat_management
    product: m365
detection:
    selection:
        eventSource: SecurityComplianceCenter
        Payload|contains|all:
            - 'New-ComplianceSearchAction'
            - 'Export'
            - 'pst'
    condition: selection
falsepositives:
    - Exporting a PST can be done for legitimate purposes by legitimate sources, but due to the sensitive nature of PST content, it must be monitored.
level: medium

False positives

  • Exporting a PST can be done for legitimate purposes by legitimate sources, but due to the sensitive nature of PST content, it must be monitored.

References

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