Senator Elizabeth Warren today launched an investigation into Equifax's data breach, which exposed the personal information of 143M Americans to criminal hackers.

The embattled Atlanta-based company hired Edelman to handle its data breach crisis. Edelman representatives declined to comment about its work.

Equifax

In a letter to Equifax CEO Richard Smith, Warren said she was "troubled" by what is described as "one of the largest risks to personally sensitive information in recent years and by the fact that it represents the third recent instance of a data breach of Equifax or its subsidiaries that has endangered America's personal information."

The Massachusetts Democrat also expressed "deep concerns" about the initial response by Equifax, which occurred 40 days after the breach.

Warren is introducing legislation to provide consumers with free credit freezes and plans to gather information to determine if broader federal laws are required to further protect consumers.