RBI has asked banks to follow the instructions of government organisation CERT-In to prevent the attack by ransomware, "WannaCry", which has impacted various IT networks in over 150 countries.Indian Computer Emergency Response Team (CERT-In) has come out with list of dos and don'ts and webcast on how to protect networks from the global ransomware attack. Once infected, a computer's files are encrypted and given a [.] WCRY file extension. Its hackers demanded an initial ransom of $300 but later it increased the ransom up to $600 in Bitcoin. That's why it's called ransomware.
Microsoft users with Windows 8.1 and Windows 10 should use Windows Defender, while those with Windows 7 and Windows Vista should use Microsoft Security Essentials.
Other tools from the presumed NSA toolkit published by the Shadow Brokers have also been repurposed by criminals and are being sold on underground forums, researchers said. But this bug has already affected many systems which had not installed the latest security updates.
The agency and its partners in the global security community are now in a "sort of cat-and-mouse" competition with hackers, as variants of the software that foil previous solutions emerge, the official says.
To begin with, the worm has been nearly too successful, having hit more than 200,000 victims - many times more than are usually caught out by ransomware aimed at large organisations.
Sixteen National Health Service organizations in the United Kingdom were hit, and some of those hospitals canceled outpatient appointments and told people to avoid emergency departments if possible.
Other high-profile victims include hospitals in Britain, the Spanish telecoms giant Telefonica, French carmaker Renault, US package delivery company FedEx, Russia's interior ministry and the German rail operator Deutsche Bahn.
Microsoft, which on Friday took the unusual step of issuing a custom security update for users whose systems no longer receive regular support, has urged users with older versions of Windows to patch the vulnerability as soon as possible. So even people with older computers should go update them.
Apple is not invulnerable to ransomware attacks, "a common misconception", one expert tells CNBC. Bad guys generally target Windows far more than Apple's operating system because there are vastly more computers running Windows around the world.
Install Microsoft's official patch.
In 2016, Motherboard reported hospitals across the United Kingdom run old, outdated Windows systems - legacy technology that no longer receives updates.
Infected computers appear to largely be out-of-date devices that organizations deemed not worth the price of upgrading or, in some cases, machines involved in manufacturing or hospital functions that proved too hard to patch without possibly disrupting crucial operations, security experts said.
The researcher tweeted that he initially didn't know that his actions would stop the malware.
Security experts say this attack should wake up every corporate board room and legislative chamber around the globe. Patched computers carry a much lower risk of being infected by malware or ransomware than those without an update. He warned that more people may be hit by the virus Monday when they return to work and switch on their computers.
"When any technique is shown to be effective, there are nearly always copycats", said Steve Grobman, chief technology officer of McAfee, a security company in Santa Clara, California.
The U.K. government's cyber office put it succinctly: "T$3 he way these attacks work means that compromises of machines and networks that have already occurred may not yet have been detected, and that existing infections from the malware can spread within networks".