Samenvatting

In this study we examined the developmental trajectories of hackers, based on their self-reported web defacements. During a web defacement, the content of a website is altered without permission. In total, 50,330 defacements of websites with a Dutch extension (.nl websites) were analyzed, which were executed by 3,640 defacers between January 2010 and march 2017. Using trajectory analysis, six different groups of defacers could be distinguished: two chronic groups of attackers and four groups who only defaced websites during a limited time period. These groups also differed in their motivations and modus operandi. The high frequent chronic attackers consist of less than 2% of the hackers, but were responsible for more than half of all defacements. It would therefore be most efficient when future interventions focus on this small group of chronic offenders. For future studies it would be an interesting topic to examine the content of the web defacements.