As cases of small-payment losses among KT customers occurred in succession centered on a specific area, the government launched an investigation after allegations emerged that hackers attempted to siphon off personal information by creating a virtual "ghost base station."
According to the telecommunications industry on the 10th, KT reported the breach to the Korea Internet & Security Agency (KISA) on the 8th and found an unknown base station ID in the currency histories of subscribers in the affected area. It raises the possibility that someone other than KT set up a virtual base station and used it for crimes.
The Ministry of Science and ICT said it received a report from KT that one cause of the unauthorized small-payment breach affecting customers was the connection of an illegal micro base station to the network. The ministry confirmed the possibility that the illegal base station could connect from other locations and demanded that KT take immediate measures to prevent the illegal base station from accessing the network.
KT said that among the base stations operating at the time of the investigation, there were no unknown base stations with hacker involvement or illegal micro base stations. It also restricted new micro base stations from connecting to the network starting at 9 a.m. on 9th at the ministry's request.
The Ministry of Science and ICT said, "We are conducting a thorough investigation into whether the hacker used an illegal micro base station to steal information and how the unauthorized small payments were carried out."
It added, "We plan to share the relevant details with other carriers so they can take necessary measures, and through a joint public-private investigation team, we will also conduct an in-depth probe into possible causes of the breach other than illegal base stations."
According to the Gyeonggi Nambu Provincial Police Agency, from 27th to recently, 74 reports of small-payment losses on mobile phones were filed by KT users in Gwangmyeong, Gyeonggi Province, and Geumcheon District, Seoul, stating that "unauthorized purchases of mobile gift certificates were made." The Bucheon Sosa Police Station is also investigating five reports of the same type. The total loss is estimated at about 50 million won.