Internal Revenue Service Data Breach History

This page tracks the Internal Revenue Service data breach history and cybersecurity incidents affecting Internal Revenue Service (Unknown). BreachHistory currently indexes 1 publicly disclosed or catalogued incident spanning 2015, with approximately 720 thousand records reported as exposed across all indexed events. These totals may include overlapping datasets or third-party estimates and should not be interpreted as unique affected users.

The Internal Revenue Service breach timeline includes major data breaches, cyber attacks, data leaks, credential exposures, API abuse, and other security incidents. Each incident provides details on the estimated records exposed, attack method, affected data types, and supporting public sources. Currently, 0 incidents are company-confirmed.

Largest Internal Revenue Service Data Breaches

The largest indexed incidents include the 2015 — Internal Revenue Service: Hacking, 720000 records. Record counts originating from threat actors or leak sites should be treated as estimates unless confirmed by Internal Revenue Service or a regulator. Below is the list of large data breaches:

• 2015 2015 — Internal Revenue Service: Hacking, 720000 records — about 720.0K records exposed · Catalogued incident

What Information Was Exposed?

Depending on the incident, exposed data may include health and medical (PHI) records, and other personal information (PII). The exact data varies between incidents, so review each breach page before assuming your information was affected.

Internal Revenue Service Data Breach 2026

At the time of this update, no Internal Revenue Service data breach has been catalogued for 2026. New incidents are added as official disclosures, regulatory filings, or credible cybersecurity reports become available.

What To Do If You Were Affected

If you believe your account may have been involved in a Internal Revenue Service data breach, change any reused passwords, enable multi-factor authentication (MFA), monitor your account for suspicious activity, and be cautious of phishing emails or fake breach notifications.

This Internal Revenue Service breach history is maintained by BreachHistory using public disclosures, regulatory filings, security research, and clearly labelled third-party claims. For the complete breach timeline, records exposed, incident details, and AI Breach Risk Score, explore the sections on this page.