Delta

Delta ISP is a Dutch internet service provider that operates under the aliases Delta and Delta ISP. The company delivers broadband connectivity and related internet access services to its customers. Its headquarters is situated in the Netherlands.

The provider was identified as one of several European internet service providers affected by a coordinated wave of short‑lived but disruptive DDoS attacks in August 2020. These attacks targeted organisations in Belgium, France, and the Netherlands, indicating that Delta ISP serves users across at least these three national markets. The assaults focused on the DNS infrastructure that underpins the provider’s service delivery.

During the incident, attackers employed DNS amplification and LDAP vectors, with traffic volumes peaking at approximately 300 Gbit/s. The resulting pressure caused temporary service outages for Delta ISP and coincided with extortion demands for Bitcoin payments, although the perpetrators were never definitively attributed. A separate outage experienced by CenturyLink around the same period was later traced to a misconfigured DDoS mitigation rule rather than the same attack campaign.

The publicly available sources do not disclose details about Delta ISP’s ownership structure, parent company, or subsidiary relationships. Consequently, no statements about its corporate hierarchy can be made from the supplied information. The available evidence confirms the provider’s role as a Dutch ISP that faced significant volumetric DDoS pressure on its DNS services in 2020.