Vietnam’s leading cyber security center reported Monday that at least 85,000 computers in Vietnam had their data stolen after being infected with a virus last month, raising concerns that hackers obtained important information.

Vietnam’s leading cyber security center reported Monday that at least 85,000 computers in Vietnam had their data stolen after being infected with a virus last month, raising concerns that hackers obtained important information.

According to the Hanoi-based Bach Khoa Internetwork Security Company (BKIS), hackers with servers in the US, Russia and China spread the Ramnit virus via removable drives and emails. Sometimes the virus mimics common software like Macromedia Flash Player and Windows Update to make attacks.

After infecting a computer, the virus will steal all data including passwords, which allows hackers to take control of victims’ email and bank accounts.

At the same time, the virus also opens a backdoor, allowing hackers to steal whichever data they want, BKIS said, adding that Ramnit usually operates “in silence”, making it hard to detect.

In its report, BKIS also said that at least 88 websites of agencies and businesses were hacked last month with most of the cases caused by overseas hackers, and a total of 3,608 new viruses appeared in Vietnam last month.