BEIJING, May 15 (Reuters) - Russian President Vladimir Putin said on Monday that intelligence services should beware of creating software that can later be used for malicious means - a reference to global 'ransomware' attacks that researchers say exploited a hacking tool built by the U.S. National Security Agency.

Speaking to reporters in Beijing, where he is taking part in a conference, Putin said that there was no significant damage to Russian institutions, including its banking and healthcare systems, from the computer worm known as WannaCry.

"But as a whole it is worrying, there's nothing good about it, it is a source of concern. As regards the source of these threats, I believe that the leadership of Microsoft have announced this plainly, that the initial source of the virus is the intelligence services of the United States," Putin said.

"Once they're let out of the lamp, genies of this kind, especially those created by intelligence services, can later do damage to their authors and creators," he added.

"So this question should be discussed immediately on a serious political level and a defence needs to be worked out from such phenomena."

Putin said that Russia was not behind the attack.

Around 1,000 computers at the Russian Interior Ministry have been affected, a spokeswoman for the ministry told Interfax news agency. A source familiar with the matter said the ministry did not lose any information in the attacks.

Putin said Russia had last year sought an agreement with the previous U.S, administration on cooperation in the field of cyber security, but that Washington had dragged its feet and no deal was concluded.

In a blog post on Sunday, Microsoft MSFT.O President Brad Smith appeared to acknowledge what security experts had already widely concluded: the ransomware attack that hit computers around the world on Friday leveraged a hacking tool, built by the NSA, that leaked online in April.

(Reporting by Denis Dyomkin; Writing by Christian Lowe; Editing by Mark Trevelyan) ((christian.lowe@thomsonreuters.com; +7 495 775 12 42; Reuters Messaging: christian.lowe.thomsonreuters.com@reuters.net))