The WannaCry ransomware worm that has ravaged computers around the world since Friday is expected to make heavier blows in Vietnam on Monday.
The malicious software proliferated quickly on Friday and by Sunday had afflicted 200,000 computers in more than 150 countries, crippling the networks at many businesses and schools, forcing victims to pay hundreds of dollars each to regain access to their computers, according to global media reports.
Vietnam is among the top 20 hardest hit countries, apart from China, India, Ukraine and the U.S. A New York Times animated map highlights Hanoi and Ho Chi Minh City among the most infected places in the world.
Vietnam’s cyber security centers Bkav and Vncert have issued warnings about wider impact from the “very dangerous” malware in Vietnam on Monday when office workers turn on their computers and check e-mails.
The New York Times said the software was apparently stolen from the National Security Agency’s arsenal of cyberweapons and put to use by unknown hackers.
It described the attack as one of the highest-profile computer intrusions since security experts and American intelligence agencies accused hackers acting on behalf of the Russian government of trying to influence the outcome of the 2016 American presidential election and the recent presidential election in France.
Cyber security experts around the world have also warned that new versions of the ransomware may wreak fresh havoc on Monday when employees return to work, Reuters reported.
Affected businesses include FedEx, Nissan, German rail operator Deutsche Bahn and hundreds of hospitals and clinics in the British National Health Service.
U.S. and European officials are still trying to catch the culprits. A Trump administration official who requested anonymity told the New York Times that the attack is complicated as “experts tell us that this code was cobbled together from many places and sources."