WannaCry, a type of ransomware, has infected the NHS and other organisations across the globe, including government institutions in China, Russia, the US and most of Europe.

Ransomware is a type of malicious software that restricts access to your computer or network and threatens to delete your data within an allotted time unless you pay a ransom. 

wannacry screencap

NHS England was the victim of a massive ransomware attack on 12 May, resulting in some patients' operations being cancelled.

The attack occurred after the USA's National Security Agency discovered a vulnerability in Microsoft's software called EternalBlue. This exploit was leaked by a hacker group called the Shadow Brokers earlier this year but the vulnerability was patched by Microsoft as soon as it happened.

The problem comes from older versions of Windows or those without Windows Updates, as these were not patched by Microsoft and were left open to attacks.

How does WannaCry work?

WannaCry works by encrypting data on a computer that has been infected. It then tells the user that their files have been locked and displays information on how much is to be paid and when - payment is taken in Bitcoin.

Like most malicious campaigns, this type of ransomware could arrive as an email attachment or as a download on your computer. For your system to become infected, you'll have to click on or downloading the attachment or file, which causes the program to run and infect your computer with ransomware.

Is your computer vulnerable? 

If you run an older version of Windows that is no longer supported by Microsoft, you will be vulnerable to WannaCry, according to Microsoft's blog. This includes Windows 8 and Windows XP, which the majority of NHS England trusts are using.

But if you are using Windows 10 or any of the other version such as, Windows Vista, Windows 7 and Windows 8.1 systems, you'll be protected as long as your automatic updates are enabled, which is set 'on' as standard.

How to protect your computer from ransomware

Once your system has ransomware, your choices are limited: pay or don't pay. Those are your options. 

If you do choose to pay, you need to make sure that they will release your data, and there really isn't a guarantee of that. In fact, in reality, by paying the attackers, you're really only fuelling the ransomware culture. 

Once they know you'll pay, they'll know others will too. 

Your best option for protecting yourself from ransomware is to backup your files, invest in some decrypters and create a best practice guide for such attacks.

See here for a full list of ransomware removal tools and anti-ransomware software.