SharePoint Malware File Upload

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Identifies the occurence of files uploaded to SharePoint being detected as Malware by the file scanning engine. Attackers can use File Sharing and Organization Repositories to spread laterally within the company and amplify their access. Users can inadvertently share these files without knowing their maliciousness, giving adversaries opportunities to gain initial access to other endpoints in the environment.

Rule type: query

Rule indices:

  • filebeat-*
  • logs-o365*

Severity: high

Risk score: 73

Runs every: 5 minutes

Searches indices from: now-30m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Cloud
  • Microsoft 365
  • Continuous Monitoring
  • SecOps
  • Lateral Movement

Version: 101 (version history)

Added (Elastic Stack release): 8.1.0

Last modified (Elastic Stack release): 8.6.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positives

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Benign files can trigger signatures in the built-in virus protection

Investigation guide

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Rule query

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event.dataset:o365.audit and event.provider:SharePoint and
event.code:SharePointFileOperation and
event.action:FileMalwareDetected

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 101 (8.6.0 release)
  • Formatting only
Version 100 (8.5.0 release)
  • Formatting only
Version 4 (8.4.0 release)
  • Formatting only
Version 2 (8.2.0 release)
  • Formatting only