Hackers have reportedly been launching cyberattacks on mobile carriers since 2012, specifically gaining control of gigabytes of data on unnamed government and law enforcement officials. China has vehemently rejected accusations of being involved in the attacks, adding that such allegations are “neither professional nor responsible”.

Security researchers at Boston-based Cybereason said that they are investigating a campaign dubbed Operation Soft Cell, which helped hackers steal records from 10 unnamed cell providers worldwide as part of a “massive-scale” espionage attempt against at least 20 high-ranking individuals.

Their names have not been revealed, and there has been no official confirmation of the hacking attacks.

“They [the hackers] have all the usernames and passwords, and created a bunch of domain privileges for themselves, with more than one user. They can do whatever they want. Since they have such access, they could shut down the network tomorrow if they wanted to”, Amit Serper, Cybereason's head of security research, pointed out.

Lior Div, Cybereason’s co-founder and chief executive, said, for his part, given the fact that the hacking attacks were ongoing, his company will not name the cell networks that have been affected. He only added that some of them are large providers, and that the smaller companies are in “unique and interesting” locations.

The hackers have managed to infect the mobile carriers since 2012, specifically siphoning off hundreds of gigabytes of data pertaining to individuals in government and law enforcement agencies.

According to Cybereason, hackers provided access to each user and their password, which helped them, in particular, gain information on the users’ bank accounts and data on their phone connections.

Cybereason researchers claimed that this massive hack could only be endorsed by a nation state and that the cyberattacks were allegedly staged by a China-based hacking group.

The Chinese Foreign Ministry has reportedly denied Beijing’s involvement in the hacks, stressing that China “firmly opposes” cyberattacks using the nation's infrastructure.

“Second, with the cyberspace being a highly virtual one filled with multiple actors whose behaviours are difficult to trace, one should present abundant evidence when investigating and determining the nature of a cyberspace activity. Making groundless accusations are neither professional nor responsible”, the Chinese Embassy was quoted by the computer technology news website CNET as saying.

The reported attack comes after the US Department of Commerce added the Chinese tech giant Huawei and its 70 affiliates to a trade blacklist, severely restricting their activity in the US, after several countries accused Huawei of being sponsored by the Chinese authorities and spying on their behalf.

The company, as well as Beijing, have vehemently denied the allegations and dismissed Washington's attempts to limit Huawei’s activities.