About 20 percent of Internet servers at Japanese companies use deficient software that leaves them vulnerable to attacks by hackers, a Tokyo-based nonprofit organization said Wednesday.
The Network Risk-Management Association said its findings are based on a survey conducted in late February that involved about 170,000 servers with Internet domain names that include the ".co.jp" suffix often used by Japanese companies.
About 30,000 servers had software that manufacturers have said is faulty and in need of repair, the group said.
It added that under current conditions, a systematic attack using 100 personal computers could halt or overcome 120,000 of the servers in the survey in about 10 minutes.
The survey shows the types of operating systems on 110,000 servers and applications on 150,000 servers.
The use of such servers exposes computer systems to hacker attacks, which may entail data theft or the use of a server to take over other computers, according to the group.
More than 90 percent of the servers in the survey had software that had not been updated.