2.3 Ensure Safe Links for Office Applications is Enabled

Warning! Audit Deprecated

This audit has been deprecated and will be removed in a future update.

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Information

Enabling Safe Links policy for Office applications allows URL's that existing inside of Office documents opened by Office, Office Online and Office mobile to be processed against Defender for Office time-of-click verification.

Rationale:

Safe Links for Office applications extends phishing protection to documents that contain hyperlinks, even after they have been delivered to a user.

Impact:

User impact associated with this change is minor - users may experience a very short delay when clicking on URLs in Office documents before being directed to the requested site.

NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.

Solution

To enable Defender for Office Safe Links policy for Office, use the Microsoft 365 Admin Center:

Under Admin centers click Security.

Under Email & collaboration select Policies & rules

Select Threat policies then Safe Links

Click on the policy, a new pane should open on the right hand side.

Under Protection settings click Edit protection settings :

Under Action un unknown or potentially malicious URLs in messages select On - URLs will be rewritten and checked against a list of known malicious links when user clicks on the link.

Under Action on unknown or potentially malicious URLS within Microsoft Teams select On - Microsoft Teams will check against a list of known malicious links when user clicks on the link; URLs will not be rewritten.

Select Apply real-time URL scanning for suspicious links and links that point to files

Select Apply Safe Links to email messages sent within the organization

Check Do not let users click through to the original URL.

Select Save

To enable the Safe Links policy for Office 365, use the Exchange Online PowerShell Module:

Connect using Connect-ExchangeOnline.

Run the following PowerShell command:

New-SafeLinksPolicy -Name 'My SafeLinks Policy' -IsEnabled $true -AllowClickThrough $false -EnableSafeLinksForTeams $true -ScanUrls $true -DeliverMessageAfterScan $false -EnableForInternalSenders $true -DoNotAllowClickThrough $true

See Also

https://workbench.cisecurity.org/files/3729