List of data breaches and cyber attacks in May 2021 – 116 million records breached

You can find June 2021’s list of data breaches and cyber attacks here.

For the second month in a row, ransomware has dominated our list of data breaches and cyber attacks. Of the 128 publicly disclosed incidents that we discovered in May, more than 40% of them were ransomware attacks.

But, of course, the nature of ransomware attacks makes it hard for organisations to determine how many records were affected. That partially explains why May’s total of 115,861,330 breached records is comparatively low.

By contrast, we disclosed 1 billion breached records in April, and almost 4 billion in the first four months of the year.

As always, you can find the full list of incidents below, with those affecting UK organisations listed in bold.

Cyber attacks

If you find yourself facing a cyber security disaster, IT Governance is here to help. Our Cyber Incident Response service provides the help you need to deal with the threat, as our experts guide you through the recovery process.

They’ll review the breach, mitigate the damage and ensure that you are up and running again as soon as possible.


Data breaches

Human error is to blame for 88% of data breaches in the UK

Financial information

Malicious insiders and miscellaneous incidents

In other news…


  1. raveena aher 8th June 2021
  2. Greg 9th June 2021