Korean cybersecurity authorities estimate that around 9.6 million accounts may have been affected by a recent cyberattack at Kyowon Group, a local education service provider, informed sources said Wednesday. The estimate by a government investigation team that includes the Korea Internet & Security Agency comes after Kyowon Group reported a possible breach on Monday, saying it had detected traces of a ransomware attack. Kyowon said it became aware of abnormal activities in its internal system Saturday and later identified a possible data breach. The authorities estimate that 600 of the company's 800 servers fall within the scope of the breach. The investigation team estimates Kyowon Group's eight affiliates held 13 million members in total, a figure that narrows to 5.54 million after removing overlaps. The 9.6-million estimate counts users holding more than one account. As Kyowon Group operates a wide range of businesses, including tutoring, home appliance rentals and funeral services, experts said the number of victims could be substantial. Kyowon Group has yet to confirm whether its memb