TOKYO, Oct 26 : Japanese companies are moving to pay compensation to users following waves of cyberattacks that have disrupted internet services and raised concerns about economic stability.

GMO Internet said customers would be compensated for losses stemming from unauthorised access following a cyberattack on its foreign exchange trading service, and all customers would receive 5,000 yen ($32) as "an initial gesture of good faith," CEO Masatoshi Kumagai said in a blog post on Sunday.

The move comes after Japan said on Friday it would set up a team to simulate cyberattacks using AI to identify weaknesses in technology systems as organisations scrambled to curtail risks from flaws in the PHP programming language that underpins much of the internet.

Shares of GMO, which had a market value of $2.6 billion as of Friday's close, slumped 11 per cent in Tokyo in the morning, compared to flat trading in the benchmark index.

Japanese companies are being roiled by attacks with experts saying AI is helping automate tasks from scanning for software vulnerabilities to crafting phishing campaigns, making cybercrime faster, cheaper and harder to detect.

Government and company websites in Japan, Europe and elsewhere went offline last week after the disclosure of critical vulnerabilities in the PHP programming language prompted millions of hacking attempts.

GMO Internet has made a request to the Japanese government to apply cyber defence measures in response to the cyberattack.

The company said it had received a demand for money from a party believed to be behind the attack, along with a threat to disclose company and customer information if it did not comply.

GMO Internet said it would not comply with the demand and would respond to the incident in coordination with police and other authorities.

Separately Park24, which operates the Times car-sharing service, said on Friday it would make 3,000 yen payments to customers following a personal data breach.