Hackers steal sensitive law enforcement data in a breach of the U.S. Marshals Service

U. S. Marshals Service Director Ronald L. Davis speaks during a violent crime prevention summit in Jackson, Miss., on Jan. 5. The agency has revealed it was the victim of a cyberattack last week in which hackers stole sensitive data. (Rogelio V. Solis/AP)

The oldest U.S. federal law enforcement agency, the U.S. Marshals Service, has revealed it was the victim of a cyberattack last week in which hackers stole sensitive data.

According to a U.S. Marshals spokesperson, the "major incident" impacted a "standalone" computer system which contained records about targets of ongoing investigations, employee personal data and internal processes.