A day after the WannaCry ransomware cyber attack seemed to be slowing down, media reports have suggested that IT firms in the Silicon Valley of India, Bangalore, have been put on high alert. The Reserve Bank of India, however, said a Windows security update could prevent and protect the institutions from any breaches.
That means an out-of-date, unsupported operating system is more popular than any version of Windows 8, any version of Mac OS X, and Linux.
Brad Smith, Microsoft's chief counsel, said Sunday in a company blog post that by keeping software vulnerabilities secret from vendors, governments open up users to attacks like Friday's WannaCry - or WannaCrypt/WanaCrypt - hack in which malware locked down computers worldwide while demanding hefty sums for freedom.
Professor Clark said more information on protecting your computer was available via the IT security company Sophos and the National Cyber Security Centre, among other sources.
Then there's the US government, whose Windows hacking tools were leaked to the internet and got into the hands of cybercriminals.
Microsoft should know that there are people, small businesses, schools and hospitals that still use older version of Windows, such as XP (which came out in 2001).
So far no clues have been uncovered as to who was behind the malicious software, which locks users' computer files and demands a ransom payment of US$300 (S$418) to US$600 to unlock them.
On top of that, critics say, the government didn't notify companies like Microsoft about the vulnerabilities quickly enough.
With global security reports counting India amongst the worst affected countries, public and private agencies have been working overtime to firewall their systems from any possible attack.
The government has long acknowledged the need to update its old IT systems.
The ransomware works by exploiting a vulnerability in Microsoft Windows.
Most of the 200,000 victims of the attack were in Europe and Asia.
It comes as the former US national intelligence director said the global "ransomware" attack could grow much larger when people return to work. Although Microsoft officially dropped support for Windows XP in 2014, it issued a security update two months ago that would have prevented WannaCry from spreading - if companies had bothered to install it.
Mac or Linux users are at the moment safe from harm, but there remains a risk they could be infected via the intranet once a member computer is infected.
"I'm surprised that it took this long for someone to use the ShadowBrokers leak", said Georgia Weidman, founder and CTO of the Shevirah cyber-security company, who noted that the malware exploit a vulnerability in Windows that's existed for almost a decade.
In any case, WannaCry spread so rapidly because of a program called EternalBlue, developed by the US National Security Agency to take advantage of a major flaw in Microsoft's Windows operating system.