Hackers who breached UnitedHealth's tech unit in February potentially stole a third of Americans' data, the largest U.S. health insurer's CEO told a Congressional committee on Wednesday.

The ransomware gang that hacked into U.S. health tech giant Change Healthcare used a set of stolen credentials to remotely access the company's systems that weren't protected by multifactor authentication (MFA),

In a notable cybersecurity lapse, hackers infiltrated Change Healthcare, a major U.S. health tech firm, through stolen access credentials and the absence of multi-factor authentication (MFA), stated the CEO of its parent company UnitedHealth.

SAN FRANCISCO (Reuters) - Hackers breached UnitedHealth's tech unit on Feb. 12 by using stolen login credentials that gave them remote access to its network, the largest U.S. health insurer will testify before a House panel this week.