Delivery company FedEx has confirmed it is suffering a malware attack.

There are many types of malware that affect a computer ranging from those that steal your information to those that just delete everything on it. Ransomware, on the other hand, prevents users from accessing their devices and data till a certain amount is paid to its creator as ransom.

An official with the ANSSI cybersecurity agency told The Associated Press that it has not detected any French targets of the new ransomware so far.

Why are businesses vulnerable to ransomware?

Krishna Chinthapalli, a doctor at Britain's National Hospital for Neurology & Neurosurgery who wrote a paper on cybersecurity for the British Medical Journal, said many British hospitals still use Windows XP software, introduced in 2001.

The attack, which locked up computers and held users' files for ransom, was believed the biggest of its kind ever recorded. The hack happened four weeks before a British general election in which national security and the management of the state-run National Health Service are important issues.

Mikko Hypponen, chief research officer at the Helsinki-based cybersecurity company F-Secure, called it "the biggest ransomware outbreak in history".

More than 75,000 computers in 99 countries were compromised in Friday's attack, with a heavy concentration of infections in Russian Federation and Ukraine, according to Dutch security company Avast Software BV.

"It has a "hunter" module, which seeks out PCs on internal networks", said Kurt Baumgartner, the principal security researcher at Kaspersky Lab told CNN. Once infected, an organization isn't left with many options, said Geraghty. Russia's health ministry said its attacks were "effectively repelled".

She did not elaborate on how the six remaining health groups were affected or where they were located.

(AP Photo/Matt Dunham). An exterior view shows the main entrance of St Bartholomew's Hospital, in London, one of the hospitals whose computer systems were affected by a cyberattack, Friday, May 12, 2017. The committee denied the reports. In the U.S. FedEx was hit.

Notable organisations affected by the virus since Friday include the National Health Service (NHS) in the United Kingdom, along with Telefonica in Spain. In light of Friday's attacks, Microsoft announced that it's making the fixes free to all.

Specifically, it works by exploiting a Windows vulnerability that the U.S. National Security Agency may have used for spying.

Ransomware attacks have become an increasingly popular crime based on the relative ease of deployment, which often occurs through email phishing attempts.

In a statement Saturday, Europol's European Cybercrime Centre, known as EC3, said the attack "is at an unprecedented level and will require a complex global investigation to identify the culprits".

As in Friday's attack, the payment can go up if it is not made within a short time frame.

"Otherwise, such an attack can be technically un-investigable", the statement said.

A global cyberattack described as unprecedented in scale forced a major European automaker to halt some production lines while hitting schools in China and hospitals in Indonesia on Saturday, though it appeared to die down a day after its launch.

A massive ransomware attack is now spreading like a tsunami around the world, hitting high profile targets like UK's National Health Service and disabling Spain's Telefonica carrier. He said that mobile communications haven't been affected.

Prime Minister Theresa May said it wasn't just Britain.

There is no evidence patient data has been compromised, NHS Digital has said.

Sometimes a user may not be immediately aware the computer is infected.

Similar widespread attacks have been reported in Spain and other countries.

Spain, meanwhile, took steps to protect critical infrastructure in response to the attack.

Many users haven't updated their computers from Windows XP and as Microsoft has ended its support for Windows XP, computers running that operating system were among the most impacted in the recent attack.

"Our analysis indicates the attack, dubbed 'WannaCry, ' is initiated through an SMBv2 remote code execution in Microsoft Windows", the piece continues.

The attack affected emergency services in some locations, and patients were urged to avoid visits to the emergency room unless absolutely necessary.

The malware is spread by taking advantage of a Windows vulnerability that Microsoft released a security patch for in March.

There were no details on which companies were targeted or the origin of the attack.

Across England on Friday, as well as at a handful of facilities in Scotland, internal tech systems were down in hospitals ranging from the center of London to rural parts of the country's south and north.

At least 16 organisations within the NHS, some of them responsible for several hospitals each, reported being targeted.