Rec: 6.2.3 - Validate Test-IdentifyExternalEmail.ps1, ELevel: E3, ProfileLevel: L1, IG1: FALSE, IG2: FALSE, IG3: FALSE, Connection: EXO

[DrIOSX]

Validation for Test-IdentifyExternalEmail.ps1

Recommendation Details

• Recommendation: 6.2.3
• Description: Ensure email from external senders is identified
• ELevel: E3
• Profile Level: L1
• CIS Control: 0
• CIS Description: Explicitly Not Mapped
• Implementation Group 1: FALSE
• Implementation Group 2: FALSE
• Implementation Group 3: FALSE
• Automated: TRUE
• Connection: EXO

Test-IdentifyExternalEmail.ps1

Tasks

Validate recommendation details

• [ ] Confirm that the recommendation details are accurate and complete as per the CIS benchmark.

Validate test for a pass

• [ ] Confirm that the automated test results align with the manual audit steps outlined in the CIS benchmark.
  • Specific conditions to check:
  • Condition A: External tagging is enabled using PowerShell for all identities.
  • Condition B: The BypassAllowList only contains email addresses the organization has permitted to bypass external tagging.
  • Condition C: External sender tag appears in email messages received from external sources.

Validate test for a fail

• [ ] Confirm that the failure conditions in the automated test are consistent with the manual audit results.
  • Specific conditions to check:
  • Condition A: External tagging is not enabled using PowerShell for all identities.
  • Condition B: The BypassAllowList contains unauthorized email addresses.
  • Condition C: External sender tag does not appear in email messages received from external sources.

Add notes and observations

• [ ] Compare the automated audit results with the manual audit steps and provide detailed observations.
  • Automated audit produced info consistent with the manual audit test results? (Yes/No)
  • Without disclosing any sensitive information, document any discrepancies between the actual output and the expected output.
  • Document any error messages, removing any sensitive information before submitting.
  • Identify the specific function, line, or section of the script that failed, if known.
  • Provide any additional context or observations that might help in troubleshooting.

If needed, the helpers folder in .\source\helpers contains a CSV to assist with locating the test definition.

[DrIOSX]

Mail flow rules using external tagging will need to be disabled before enabling this to avoid duplicate [External] tags.

[DrIOSX]

Base PowerShell Audit:

Get-ExternalInOutlook