(Reuters) - Hong Kong-based digital toy and gadget maker VTech Holdings Ltd (HK:0303) said FireEye Inc's (O:FEYE) 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 spokesman for VTech declined to comment on which governments were looking into the attack or say whether they had identified any suspects.
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 (N:TGT) and last year's attack on Sony Pictures Entertainment (T:6758).
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. FBI spokeswoman Carol Cratty declined comment when asked if the U.S. law enforcement agency was investigating the attack.
Britain's data privacy regulator, the Information Commission's Office (ICO), said it was investigating the breach. The cyber crime unit of Britain's National Crime Agency declined to comment on whether they are providing any assistance in the investigations.
VTech's European headquarters are located in Britain - in Abingdon, south of Oxford.
In Europe, national data regulators typically defer to the country where an organization is headquartered to take the lead on probes. A spokesperson for the ICO said part of its enquiries was to determine which organization would take charge.
Of the 6.4 million children and 4.9 million adults impacted by the breach, nearly 5 million victims live in Europe, including 2.8 million children, according to VTech.
More than 2 million were affected in France, including 1.17 million children, followed by Britain, with 1.29 million affected, including more than 727,000 kids.
The VTech data breach also affected significant numbers in Germany, Spain, Belgium and the Netherlands.