At a conference Thursday on protecting bank customers, Trieu Manh Tung, deputy head of the ministry's department of cyber security and high-tech crime prevention, said scammers could impersonate anyone to trick people online thanks to the Internet's anonymity.
Last year the police busted a scamming group with 300 people, complete with an office for working and a canteen for lunch, and even research and training departments, he said.
Scammers have adapted to the fact that banks now require biometric authentication, he said.
Criminals now impersonate bank employees and ask people to furnish personal information.
"Customers just need to click on a single link, and they could lose all their money in just one or two seconds."
Scamming organizations now operate across borders, and many not only work in Vietnam but also elsewhere, making it hard for authorities to deal with them, he added.