question about "Wanna cry virus"

[net guru]

Hello experts, 

can some please briefly explain how does the "Wanna cry virus" that went viral these days work ? and was the loophole in windows' system that have been used ? .

and finally is there any measures windows user should take starting with blocking SMB port on the windows firewall ? 

thank you so much for any explanation ! 

[Rahul Govindan · Accepted solution]

The Cisco Talos log has a very detailed explanation of this attack. 

http://blog.talosintelligence.com/2017/05/wannacry.html

The best protection against this attack is patching your windows systems. You can block inbound access to SMB ports also. But new variants of the ransomware may use other methods to infect systems. So applying the latest MS patch should be the help there. 

[net guru]

thank you so much for the reply , all i needed is an insured document to read.