As of Wednesday, there had been no reports of Thai state agencies or private enterprises being affected by Petya, said Surangkana Wayuparb, executive director and chief executive officer of Electronic Transactions Development Agency (ETDA).

The agency operates Thailand Computer Emergency Response Team (ThaiCERT) which is spearheading the improved security.

Surangkana said ThaiCERT was in contact with agencies responsible for critical infrastructures immediately after reports of a massive global ransomware attack on Tuesday night.

International experts said Petya is more sophisticated than Wannacry, prompting many companies in the West to shut down their computer systems.

Thailand is in the process of setting up a national cybersecurity agency to take charge of the crucial issue as the country focuses on its digitalisation drive for the economy and society, resulting in more vulnerabilities to cyber attacks.

Surangkana said the new agency should be operational soon since more malware and ransomware programmes will become more common due to the widespread use of Internet as well as the rising number of Internet of Things devices and the migration of computing facilities to the cloud service.