South Korea raised its cybersecurity alert on Sunday amid growing concerns about the WannaCry ransomware cyberattack that has spread across the world.
The Korea Internet & Security Agency said four companies have reported to the state computer security agency that they were affected by the malicious software over the weekend.
Seven companies have consulted with it for two days and four of them registered official damage reports. The agency said it will provide technical support to them.
Private security agencies found that about 4,000 domestic Internet Protocol addresses have been affected, most of them connected with the computer networks of overseas operations, industry sources said.
ESTsecurity, a computer security company, said it has detected more than 2,000 attacks on domestic sites.
The Ministry of Science, ICT and Future Planning raised the cyberattack alert by one notch from "concern" to "caution" as of 6 p.m. Sunday. (Yonhap)
The ministry said damages are expected to soar on Monday when Koreans return to work. (Yonhap)