An adviser to Ukraine's interior minister said earlier in the day that the virus got into computer systems via "phishing" emails written in Russian and Ukrainian created to lure employees into opening them.
"As ransomware also typically spreads via email, customers should exercise caution when opening unknown files", the Microsoft spokesperson said. Through this technique, hackers hold your computer hostage by encrypting nearly all the data on your device until you pay the ransom amount asked by the hacker.
In Ukraine, Yevhen Dykhne, director of Boryspyl Airport, said it had been hit by a cyber attack.
According to Mr. Patanmi, the malware is spreading using a vulnerability in Microsoft Windows that was patched in March 2017 - the same bug that was exploited by the WannaCry ransomware.
"Microsoft antivirus software finds this ransomware and protects against it", TASS cited Davydova as saying.
Ukrainian officials confirmed a possible link to MeDoc.
Russia's central bank said there were isolated cases of lenders' IT systems being infected.
Operations at one of the three terminals of Jawaharlal Nehru Port (JNPT) in Mumbai, India's largest container port, were disrupted.
The malware that is used by the attackers is believed to be worse than in previous instances, because users are not even able to launch their computers.
"A massive ransomware campaign is now unfolding worldwide", said Romanian cybersecurity company Bitdefender, where analyst Bogdan Botezatu said that it appeared to be almost identical to GoldenEye, one of a family of hostage- taking programs that has been circulating for months.
Also at risk are embedded computer systems - for example those that run public infrastructure - which are often connected to networks but not updated. We continue to assess the situation.
A National Security Agency spokesman referred questions about the attack to the Department of Homeland Security.
The statement also said that all "technological systems of the station operate in the normal mode", but that "in connection with the cyberattack, the Chernobyl nuclear power plant website is not working".
The new strain, which has similarities to a well-known software called Petya but may be a modified or wholly new version, has already caused a significant amount of damage in Europe and has moved to the US. Petya means "Little Peter, " in Russian, leading some to speculate the name referred to Sergei Prokofiev's 1936 symphony "Peter and the Wolf, " about a boy who captures a wolf. "That should stop the attack, but your computer can still transmit the "disease" to others". Petya was for sale on the so-called dark web, where its creators made the ransomware available as "ransomware as a service" - a play on Silicon Valley terminology for delivering software over the internet, according to the security firm Avast Threat Labs.
The attack targets Windows PCs and takes the form of ransomware, encrypting users' files and demanding payment in exchange for decryption.
What should a person do if he/she gets affected by the ransomware?