Cyber incidents caused by attacks from outside

If a cyberattack has (adverse) consequences for a firm, it is referred to as a cyber incident. This study focuses solely on incidents resulting from external attacks (i.e. not originating from within the firm).

The following three types of incidents are identified:

1) failure of ICT systems, for example due to a DDoS or ransomware attack
2) data destruction or data corruption caused by infection from malicious software or unauthorised digital access to a firm’s systems
3) data disclosure through cyber intrusion, phishing or pharming.

The questions on cyber incidents relate to the previous year: in the 2025 survey, businesses were asked whether they had been affected by the above-mentioned cyber incidents in 2024.