Earlier today a massive ransomware virus attack spread to the computer systems of hundreds of private companies and public organisations across the globe. The software locks computers and asks for a digital ransom before control is safely returned. Ransomware attacks are not new, but the speed of the recent hackings has alarmed security experts. In a few hours, the malware had already infected victims in at least 74 countries, including Russia, Turkey, Germany, Vietnam, and the Philippines - and is thought to be spreading at a rate of five million emails per hour. The hack was carried out as hospitals and doctors' surgeries in England were forced to turn away patients and cancel appointments after the attack crippled the NHS. Although cyber extortion cases have been rising for several years, they have to date targeted small- and mid-sized organisations. But an attack on such a large scale has never been seen before. Who could be behind the string of attacks, and whether they are connected, remains a mystery. What is ransomware? Ransomware is a type of malicious software that criminals use to attack computer systems. Hackers often demand the victim to pay ransom money to access their files or remove harmful programmes. The aggressive attacks dupe users into clicking on a fake link – whether it's in an email or on a fake website, causing an infection to corrupt the computer. In some instances, adverts for pornographic website will repeatedly appear on your screen, while in others, a pop-up will state that a piece of your data will be destroyed if you don't pay. In the case of the NHS attack, the ransomware used was called Wanna Decryptor or 'WannaCry' Virus. What is the WannaCry virus? The WannaCry virus targets Microsoft's widely used Windows operating system. The virus encrypts certain files on the computer and then blackmails the user for money in exchange for the access to the files. It leaves the user with only two files: Instructions on what to do next and the Wanna Decryptor program itself. When opened the software tells users that their files have been encrypted and gives them a few days to pay up or their files will be deleted. It can quickly spread through an entire network of computers in a business or hospital, encrypting files on every PC. What are the hackers asking for? The hackers are asking for payments of around £230 ($300) in Bitcoin. Payments can be sent to at least two anonymous Bitcoin wallets that are routed through the Dark Web and cannot be traced. Payments appear to be being made to the Bitcoin addresses given in the NHS attack. It is not possible to say who has paid the ransom so far. Who could be behind the attacks? The ransomware attack is one of the largest ever seen. One cyber-security researcher tweeted that he had detected 36,000 instances of the ransomware, called WannaCry and variants of that name. Some of the organisations affected do not appear to have been specifically targeted by the attack, meaning it could be spreading at random. A number of different groups could be behind the string of hackings. While it is possible a large cyber criminal gang are responsible, the attacks could also be government-orchestrated. It has previously been suggested that a string of ransomware attacks on US companies last year were perpetrated by Chinese government hackers. How to protect yourself from ransomware Thankfully, there are ways to avoid ransomware attacks, and Norton Antivirus has compiled a list of prevention methods: 1. Use reputable antivirus software and a firewall 2. Back up your computer often 3. Set up a popup blocker 4. Be cautious about clicking links inside emails or on suspicious websites 5. If you do receive a ransom note, disconnect from the Internet 6. Alert authorities FIVE STEPS TO MORE SECURE ONLINE OPERATIONS Even using this checklist can't guarantee stopping every attack or preventing every breach. But following these steps will make it significantly harder for hackers to succeed. 1) Enable two-factor authentication (2FA). Most major online services, from Amazon to Apple, today support 2FA. When it's set up, the system asks for a login and password just like usual – but then sends a unique numeric code to another device, using text message, email or a specialized app. Without access to that other device, the login is refused. That makes it much harder to hack into someone's account – but users have to enable it themselves. 2) Encrypt your internet traffic. A virtual private network (VPN) service encrypts digital communications, making it hard for hackers to intercept them. Everyone should subscribe to a VPN service, some of which are free, and use it whenever connecting a device to a public or unknown Wi-Fi network. 3) Tighten up your password security. This is easier than it sounds, and the danger is real: Hackers often steal a login and password from one site and try to use it on others. To make it simple to generate – and remember – long, strong and unique passwords, subscribe to a reputable password manager that suggests strong passwords and stores them in an encrypted file on your own computer. 4) Monitor your devices' behind-the-scenes activities. Many computer programs and mobile apps keep running even when they are not actively in use. Most computers, phones and tablets have a built-in activity monitor that lets users see the device's memory use and network traffic in real time. You can see which apps are sending and receiving internet data, for example. If you see something happening that shouldn't be, the activity monitor will also let you close the offending program completely. 5) Never open hyperlinks or attachments in any emails that are suspicious. Even when they appear to come from a friend or coworker, use extreme caution – their email address might have been compromised by someone trying to attack you. When in doubt, call the person or company directly to check first – and do so using an official number, never the phone number listed in the email. - Arun Vishwanath, Associate Professor of Communication, University at Buffalo, State University of New York Why would attacks target hospitals? The main reason medical institutions and the NHS are targeted is because they have vast amounts of patient data at their disposal. Jean-Frederic Karcher, Head of Security at Maintel, said: 'Medical information can be worth 10 times more than credit card numbers on the deep web. 'Fraudsters can use this data to create fake IDs to buy medical equipment or drugs, or combine a patient number with a false provider number and file fictional claims with insurers.' How did the hackers initiate the attack? Some have suggested that the ransomware hackers may be using a US National Security Agency (NSA) cyber weapon. Last month a separate hacking group released passwords to a range of NSA hacking tools as an attack on Donald Trump's presidency. And it now appears one leaked NSA tool, an exploit of Microsoft Windows called EternalBlue, is being used as one method for rapidly spreading WannaCry ransomware around the world, Forbes reports. UK-based researcher Kevin Beaumont tweeted that WannaCry was using the NSA attack, which exploited a now-patched Microsoft Windows vulnerability, also known as MS17-010. NSA security researchers initially developed the tool to hack into the computers of suspected terrorists and spies. 'MS17-010 is the best candidate for this ransomware attack,' Matthew Hickey, co-founder of British cybersecurity training hub Hacker House, told Forbes. 'It highlights the dangers of NSA exploits being released to the public. I have made the point repeatedly that people should not downplay the significance of the recently released tools and exploits. 'They are weapons-grade and available for easy use. Attacks like the one hitting the NHS are an easy way for criminals to capitalize on these exploits.' Hours after news of the cyber attacks broke, a Microsoft spokesman revealed that customers who were running the company's free antivirus software and who had enabled Windows updates were 'protected' from the attack. It raises questions about why NHS computers using the operating system were not shielded from the ransomware.