A representative of US-based Nexusguard released the information at a conference in Hanoi which focused on how to protect networks and data from DDoS attacks targeting organisations and businesses.
A DDoS is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to the internet.
Incoming traffic flooding the victim originates from many different sources, effectively making it impossible to stop the attack simply by blocking a single source.
According to the company, VNPT, Viettel, FPT and Vietnamobile were among the enterprises most attacked by DDoS in the period from January 1 to April 15 this year.
Nexusguard data also showed that the country ranked fourth globally in terms of IP address spoofing.
Nguyen Huy Dung, deputy head of the Authority of Information Security said that the conference themed "Protect network and data from DDoS attacks aiming at organizations and businesses" is of significance in the fourth Industrial Revolution.
The event would help increase the awareness of service providers and State agencies about DDoS attack tendencies, and how to avoid, he added.