Nearly 437,700 email accounts with addresses ending with ".vn" (Vietnam) have been leaked with personal information and passwords.
The mass exposed happened through foreign social networks and online services.
Of the exposed email accounts, 930 have addresses ending with "gov.vn" (governmental agencies of Vietnam).
The Vietnam Computer Emergency Response Team (VNCERT) under the Vietnamese Ministry of Information and Communications released the information, reported China's Xinhua news agency.
Many breached email accounts belong to Vietnam's major economic groups and important infrastructure developers, said VNCERT.
A lot of staff of state agencies and corporations uses their organisations' email accounts to register for their personal accounts of foreign social networks and online services, added VNCERT.
VNCERT said Vietnam has faced many cybersecurity issues, like low public awareness about online security with more and more websites being defaced, and malware spreading among computers.
