Research methodology

We identify incidents from a range of publicly available sources (listed in our weekly round-ups), including news articles, PR statements, and feeds by security researchers. We record these incidents, along with quantifiable data points for each, in a spreadsheet. Note that we only record incidents where we have a reasonable degree of confidence that it’s genuine, e.g. because the report is coming from a reputable source, or because samples have been provided.

We do our best to present the data as accurately and objectively as possible, but inevitably deal with lots of blurry lines. There are also the inherent limitations of working with breaking news, where we often lack detail at initial disclosure.

Please also be aware that we log incidents manually in a spreadsheet, from which we analyze and quantify the numbers. While we do our utmost to avoid inputting errors, when we typically record hundreds of incidents a week, some mistakes may slip through.


Month and year recorded

We record incidents by the month and year that they came into the public domain – not when the incident took place, given that it usually takes time for the victim to become aware of the incident, and more time before publicly disclosing it.

Again, an inherent limitation of working with breaking news is that, often, more information about the incident comes to light later. We do backtrack our data in our spreadsheet in such scenarios, which our annual report will reflect, but this causes some discrepancies between our weekly and monthly reports, and our annual one.


Region and country

We record the region (continent) and country as where most affected individuals are located. If we don’t have this information, we record the region and country as where the organization is based. Where the organization has locations in multiple countries, we record the region and country of its headquarters.


Supply chain attacks

Incidents that originated from a third party, often an IT services or software provider. Note that relatively few supply chain attacks can have a relatively big impact on the overall figures, but that doesn’t make these attacks any less serious. Successfully exploiting a vulnerability in just one IT services or software provider could impact hundreds or even thousands of organizations.


Data breached

Where the confidentiality, integrity, and/or availability of data records have been compromised. This can include an unsecured database, data exfiltration, and even physical data breaches – for instance, lost or stolen paperwork. The hard copy data could also have been destroyed without authorization.

Note that a ‘data record’ can include personal data as well as confidential business data.

In cases where only the number of affected data subjects is reported, but we know that multiple data types had been breached per person, we still record only the number of individuals affected, because we can only record the numbers publicly disclosed. Moreover, where there is any doubt, we always err on the side of caution by reporting the lower figure.

For incidents where we only know the file size of the data breached, we use the formula 1 MB = 1 record. Given that we can’t know the exact numbers, as it depends on the types of records included (for instance, pictures and medical histories are considerably larger files than just names and addresses), we err on the side of caution by using this formula. We believe that this underestimates the records breached in most cases, but it is more accurate than not providing a number at all.


Remedial action

Reported remediation typically includes conducting a forensic analysis to establish exactly what happened (often by engaging a third-party specialist). It often also involves temporarily taking down systems to limit the impact of the security breach.

In the case of DoS (denial-of-service) attacks, where a website had been taken down by a threat actor and is live again at the time of writing, we assume that the attacked organization has taken remedial action, even if that organization hasn’t publicly acknowledged the attack or the remediation.


Notified regulator

This means that the incident involved a regulator or an equivalent authority, whether because the organization itself became aware of the breach and reported it, or because a third party reported it, or because it was the regulator or authority that uncovered the data breach.


Notified individuals

‘Individuals’ here can mean both data subjects as well as individuals affected by a service disruption. Where the organization made a clear statement of intent about notifying affected individuals as soon as it has completed its investigation, we count this as having notified individuals.