SINGAPORE - No government agencies or critical information infrastructure in Singapore were affected by global hacking attacks that hit nearly 100 countries, the Cyber Security Agency of Singapore (CSA) said.

"To date, no government agencies or critical information infrastructure (CII) in Singapore have been affected by the global hacking attacks last night," said Mr Dan Yock Hau, director of the National Cyber Incident Response Centre.

The CIIs have been notified to be on heightened alert, he added.

CSA advised organisations, businesses and members of the public to seek help from CSA's SingCERT (Singapore Computer Emergency Response Team) at singcert@csa.gov.sg or their hotline at 63235052, if they are affected.

The agency advised all Windows users to make sure their computer systems are fully patched, in an advisory on the SingCERT website.

It issued the following recommendations:

SingCERT advises all users and companies with affected systems (listed here) to ensure that their Windows-based systems are fully patched.

Users should ensure that their anti-virus software is updated with the latest malware definitions.

Users should perform file backups and store them offline in case they need to restore their systems following an attack.

A fast-moving wave of cyber attacks swept the globe on Friday, apparently exploiting a flaw exposed in documents leaked from the US National Security Agency.

The malware's name is WCry, but analysts were also using variants such as WannaCry.

The attacks used a technique known as ransomware that locks users' files unless they pay the attackers a designated sum in the virtual currency Bitcoin.

Hospitals in Britain, Russia's interior ministry, the Spanish telecom giant Telefonica, the US delivery firm FedEx and many other organisations were affected, AFP said.

The reported number of countries affected range from 74 to 99.