SEOUL, March 4 (Yonhap) -- The Web sites of South Korea's presidential office, government agencies and financial institutions came under a cyber attack on Friday, industry sources said.

The presidential office Cheong Wa Dae, the Ministry of Foreign Affairs and Trade and top lender Kookmin Bank were among some 40 institutions whose Web sites were infected by the so-called distributed denial-of-service (DDoS) from 10 a.m., AhnLab Inc. said in a statement.