The corporate network of US firm LoopPay was infiltrated by Chinese hackers earlier this year, said The New York Times.

The hackers, known as the Codoso Group or Sunshock Group, are believed to have broken into LoopPay’s network but not the system that helps manage payments.

Will Graylin, the firm’s CEO, said security experts were still sifting through evidence but there was no indication that Samsung’s systems had been infiltrated, or that consumer data had been compromised.

The breach happened in March. LoopPay was acquired by Samsung in February for more than $250 million. However, the hack only came to light in August.

LoopPay’s magnetic secure transmission (MTS) technology enables Samsung Pay to work with older, non-NFC, point-of-sale systems, a crucial advantage that the South Korean vendor talks up in competition with rivals such as Apple Pay.

The hack does not involve the firm’s point-of-sale technology but company executives will still be wary given Samsung Pay has only just launched in the US and security fears about mobile payments loom large in the mind of some consumers.

“Samsung Pay was not impacted and at no point was any personal payment information at risk,” said Darlene Cedres, Samsung’s chief privacy officer, in a statement.

“This was an isolated incident that targeted the LoopPay corporate network, which is a physically separate network. The LoopPay corporate network issue was resolved immediately and had nothing to do with Samsung Pay,” she added.

However, some experts said it might be premature to draw final conclusions given the hackers’ record of leaving back doors in hacked entities that they revisit later.