Data of 700,000 VodafoneZiggo customers exposed due to data breach

The personal data of approximately 700,000 VodafoneZiggo customers have leaked out due to a data breach, the company said on Wednesday. The telecom provider works with market research firm Blauw, which said a day earlier that someone outside the company gained access to the personal data because of a problem with one of the company's software suppliers.

This mainly concerns data such as names and e-mail addresses, according to VodafoneZiggo. "We are still conducting further investigation. As far as we know, it does not concern bank details and passwords." Scammers can use names and contact details as part of a phishing attempt, where they pose as someone else in emails or direct messages to steal sensitive information or passwords, for example.

The telecom company reported earlier in the day that customers had been affected by the data breach. But at that time it was not yet clear how many customers were involved. Previously, the Dutch national railway, NS, warned that the personal data of approximately 780,000 customers may have been involved in the same data breach.

VodafoneZiggo, Blauw and the NS have reported the leaks to the Dutch Data Protection Authority (AP).

A total of fourteen companies have been affected, according to Blauw. The market researcher learned on Friday that an unauthorized person had access to the software supplier's network. On Monday, the supplier confirmed that data had actually been stolen. The company is still investigating exactly which data was stolen or viewed by unauthorized persons. Access to the personal data has now been secured.

Blauw was not willing to say who the software supplier was, and also would not state which companies were affected. Albert Heijn, Etos, bol.com and Vattenfall are also clients of Blauw, but have said that they were not affected by the data breach. The same applies to the Efteling theme park, classified advertising website Marktplaats, restaurant home delivery service Thuisbezorgd.nl and ESPN.