Widespread disruption has hit organisations across the world in the second major cyber attack to strike in as many months.

Big business including advertising giant WPP and law firm DLA Piper were affected, while government offices in eastern Europe were affected.

A hospital in the US and pharmaceutical company Merck also fell victim, and Cadbury owner Mondelez International said it had experienced a "global IT outage" which it was working to resolve.

Government officials reported major disruption to the power grid, banks and government offices in Ukraine, where news of the attack first emerged on Tuesday.

The latest virus comes just weeks after ransomware - the name given to programmes that hold data hostage by scrambling it until a payment is made - downed systems across the globe, including the NHS in the UK.

More than 200,000 victims in around 150 countries were infected by the WannaCry or Wanna Decryptor ransomware, which originated in the UK and Spain last month, before spreading globally.

The National Cyber Security Centre, part of intelligence agency GCHQ, said it was monitoring the current "global ransomware incident".

The current ransomware is known as GoldenEye, according to Bogdan Botezatu, a senior e-threat analyst at Bitdefender.

Victims of the malware are asked to pay a 300-dollar ransom after their hard drive is encrypted, crashing their computer.

Mr Botezatu, who warned against paying any money, said on Tuesday night that the malware operators received 27 payments totalling almost 7,000 dollars in digital currency in around five hours.

He said: "I would strongly advise against paying the ransom, because this keeps this vicious circle in which hackers get enough money to fuel even more complex malware and this is why ransomware has become so popular in just three years.

"It's a billion-dollar business and the more customers they have, the more advanced the future ransomware attacks will be."

The ransomware is believed to be spreading from one computer to another using the exploit EternalBlue, which was also used in the WannaCry attack.

Mr Botezatu said GoldenEye, a more advanced version of the malware Petya, may have a number of exploits, meaning even those who patched their systems against EternalBlue after the WannaCry attack may still be vulnerable to the latest hack.

He said experts will work on trying to find a flaw in the ransomware in order to create a decryption tool, but there is no guarantee victims will get their information back.

The risk of being caught out by the ransomware can be reduced by taking careful steps.

The main step is to ensure software is up-to-date and patches and updates are installed to Windows and software providers.

The latest updates will ensure the newest form of ransomware is unable to exploit existing vulnerabilities in the system.

Primarily, the cyber attacks have focused on large companies, so be careful when opening links or downloading items at work. Make sure it is from a trusted source and the link is valid.

Some organisations may require workers to seek authorisation before downloading files from the internet.

It is also strongly recommended, whether at work or at home, that you make regular back-ups of work and important information stored on the computer.