How to defend your PC from latest ransomwares?

Petya ransomware considered to be spreading via the EternalBlue exploit in Windows PC used in the WannaCry attack few months back.

What actions has to be taken to prevent your PC from getting affected from Petya (NotPetya) ransomware?

1) Update your PC to latest releases
2) Or at least download and install this security patch from Microsoft
3) Feel your internet is slow or other situations preventing you from downloading, follow below steps to create a file named perfc in the C:\Windows folder and make it read only as said by Cyber security researcher Amit Serpe
>> Configure Windows to show file extensions. Make sure the Folder Options setting for Hide extensions for known file types is unchecked as shown...

>> Now navigate to C:\Windows folder
>> Copy and paste the notepad.exe program into same folder
>> Rename that file as perfc (without any extension type)
>> Right-click on the file and go to Properties --> General --> Check Read-Only attribute

Additionally, Disable SMB1 on Windows which is the root of latest ransomwares (WannaCry and Petya) attacks...
>> Open Control Panel --> Programs & Features --> Turn Windows features on or off.
>> In the list of options, Uncheck the checkbox associated with 'SMB 1.0/CIFS File Sharing Support' and press OK.
>>Restart your computer.

You can also try this simple tool to scan your PC against EternalBlue vulnerability.