Hackers last month disrupted more than 450 websites of Vietnamese businesses and agencies, 68 of which belonged to the state, according to a report in the Sai Gon Tiep Thi newspaper.
The Bkav Internet Security Center said Wednesday it was the largest-ever attack against Vietnamese websites on a monthly basis.
The attacks once again proved that there were too many security holes in Vietnamese websites, the center said.
Nguyen Minh Duc, director of Bkav's Internet Security Section, said the websites were so poorly equipped that average-skilled hackers could easily penetrate and deface them.
Experts said Vietnamese websites should adopt ISO/IEC 27001, an Information Security Management System (ISMS) standard, to bring information security under strict control.