The Ministry of Science and ICT said Wednesday it will investigate allegations that the North Korea-linked hacking group “Kimsuky” targeted local telecom giants KT and LG Uplus.

Vice Minister Ryu Je-myeong told lawmakers the ministry will review materials after U.S. cybersecurity outlet Prack reported that Kimsuky had attacked South Korean government agencies and telecom companies.

Both KT and LG Uplus have denied any security breach, while another firm named in the report requested forensic support from the Korea Internet & Security Agency.

Ryu said the ministry will review whether the companies’ internal checks and reports are reliable. He added that an on-site forensic review is already under way at the third company, though no evidence of intrusion has yet been confirmed.

The allegations come amid heightened concerns over Pyongyang’s cyber capabilities and their potential threat to critical infrastructure.