(Reuters) - Hong Kong-based digital toymaker VTech Holdings Ltd <0303.HK> said FireEye Inc's (FEYE.O) Mandiant forensics unit was helping the company secure its systems after a hacking attack exposed data on 6.4 million children.
VTech said it was cooperating with law enforcement worldwide to investigate the cyber attack, which surfaced last week.
A representative for VTech declined to say which law enforcement agencies it was working with or if they had identified a suspect in the case.
Mandiant will also review all aspects of how VTech handles customer information and suggest ways to strengthen the security of its user data, VTech said.
Mandiant helps victims of cyber attacks identify the extent of hacking, clean up networks and restore systems.
It has handled some of the largest breaches, including the 2013 holiday attack on Target Corp (TGT.N) and last year's attack on Sony Pictures Entertainment <6758.T>.
U.S. lawmakers on Wednesday asked VTech why it collects data on children, and how it secures that information.
At least two U.S. states also plan to investigate the breach.
(Reporting by Supantha Mukherjee in Bengaluru and Jim Finkle in Boston; Editing by Shounak Dasgupta)