Spy agency working with US, UK counterparts to track perpetrators behind hack of country's largest mobile operator

No mobile phones used by officials working in the government's major security departments have been affected by the SK Telecom hack so far, according to a National Intelligence Service document seen exclusively by The Korea Herald.
In the document dated Thursday, the NIS said no official phones used at the five government departments and agencies -- the NIS, Ministry of National Defense, Ministry of Foreign Affairs, Ministry of Science and ICT and the Presidential Security Service -- have suffered a data breach or other security incidents since the hack of the country's largest telecom provider first surfaced last month.
Although no security incidents involving official phones have been detected to date, the NIS said it was monitoring for the possibility.
According to the NIS, SK Telecom has been the sole manufacturer of official phones used by the South Korean government since April 2020.
In the document, the spy service concluded that the security functions of the officials' phones should not, in principle, be affected by the SK Telecom hack.
However, the NIS admitted that official phones, which have higher protection than normal phones, could be subject to universal subscriber identity module card duplications.
To prevent possible security breaches, all of the official phones have been subscribed to SK Telecom's USIM protection services as of April 29, the NIS said. USIM cards on the official phones were also being replaced with new ones.
The NIS said it was working closely with its counterparts in the US, UK and Singapore to identify the perpetrators behind the telecom hack.
arin@heraldcorp.com