It issued an urgent warning on Wednesday about an organized malware attack from foreign sources, saying it is a scheme against the Vietnamese government and key information infrastructure in the country.

It is possibly for both financial and political aims, it said.

"This is an intentional attack from international hackers against the Vietnamese government and its vital information infrastructure," Nguyen Khac Lich, its deputy general director, said.

"The malware used is very dangerous and well disguised. For this reason, individual users should exercise great caution while communicating online."

The malware was dispersed through disguised attachments on emails, with the contaminated files showing as normal documents (.doc). When a victim clicked on the files, the malware sneaked inside computers and stole personal information.

The contaminated computers also act as a conduit to attack other computers. Consequently, a botnet is created, and it serves as a foundation for a large-scale attack against national information systems.

The attack might result in national security information being stolen by the hackers for a long time.

The Authority of Information Security has provided tools to remove the malware on its website and the website of the ministry's Cybersecurity Emergency Response Teams/Coordination Center.

The agency reported 4,625 cyber attacks in the first nine months this year, down 43.8 percent from the same period in 2018.