Point-of-sale terminal maker Verifone is investigating an internal network breach that may have affected several firms using its hardware, according to the Krebs on Security blog.
Citing sources, Krebs says that the breach only affected Verifone's corporate network, not its payment services network.
In an internal memo to all staff and contractors, dated January 23, Verifone CIO Steve Horan says: "We are currently investigating an IT control matter in the Verifone environment," adding "All employee passwords need to be changed in the next 24 hours".
Company spokesman Andy Payment told Krebs. "We immediately began work to determine the type of information targeted and executed appropriate measures in response. We believe today that due to our immediate response, the potential for misuse of information is limited."