An integrated threat protection solution designed to detect, investigate, and respond to cyber threats across Microsoft 365 services.
The alert indicates that Microsoft Defender found personal information (such as a Social Security number) exposed in a data breach associated with nationalpublicdata.com. This is related to the National Public Data breach, where personal information like names, addresses, and Social Security numbers was exposed.
If the “Take action” screen is blank, focus on protecting the data that was reported as exposed:
- Review what was likely exposed
- The alert text already shows “Social Security number and 4 more items.” Treat this as if those items are confirmed exposed, even if the details page will not load.
- Take protective actions for the exposed data
- For any password or account credentials that might be part of the exposed data, change those passwords anywhere they are used.
- Monitor financial accounts and credit reports for unusual activity, since Social Security numbers and similar data can be used for identity theft.
- Use Microsoft’s identity theft guidance
- Follow the guidance in the Identity theft monitoring help center for steps to take based on the type of information exposed. Visit the Identity theft monitoring help center from the article about unknown breaches.
- Also review Protecting yourself from identity theft online for general best practices.
- If the breach source is shown as “Unknown”
- When Defender reports an “Unknown” breach, it means the data was found published but the original source cannot be confidently identified. The data may have been shared in forums, chat rooms, or files after the original breach.
- If a unique username or password appears (when the page does load in the future), that may help identify where the data originally came from.
- If the data is old or not relevant
- When the breach details page works again, use the options on the breach details card:
- Select More options at the bottom.
- Choose I don't recognize this info if it is not actually yours, or This info is outdated if it is no longer relevant.
- When the breach details page works again, use the options on the breach details card:
Even if the “Take action” page is currently blank, treat the alert as valid and follow the identity protection steps above.
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