DreamHost, one of the world's largest web hosting companies, said a distributed denial-of-service (DDoS) caused significant outages Thursday [Aug. 24] affecting customers of its web and email services.

The Los Angeles-based hosting provider said that an attack against part of its online infrastructure had resulted in connectivity issues affecting several aspects of its operations, ranging from its online customer support features to the hosting service used by over 1.5 million websites.

The attack targeted DreamHost's Domain Name Servers (DNS) -- digital directories that allow internet users to access specific websites without remembering their lengthy, numeric IP addresses -- and was remedied about four hours after first being detected, according to the company.

DDoS attacks involve knocking websites offline by overloading their servers with illegitimate traffic and effectively rendering them inaccessible.

Low-level attacks are capable of briefly disabling websites lacking DDoS protection, but wide-scale attacks like the one conducted last year against Dyn, an American DNS provider, caused unprecedented outages affecting some of the world's most popular websites, including Amazon and Netflix.

DreamHost customers, including the Cambridge Seventh-day Adventist Church in England and the Tale of Two Wastelands video gaming project, were among those who said their websites were unavailable Thursday due to the powerful DDoS attack.

The DDoS attack was confirmed by DreamHost as two of the company's customers made headlines in their own right over their unrelated efforts to survive scrutiny: DisruptJ20, an anti-Trump protest site, and The Daily Stormer, a white supremacist website that remerged online this week with the help of DreamHost after being all but driven off the internet.

A federal judge earlier Thursday ordered DreamHost to provide information sought by federal prosecutors investigating the riots that erupted in Washington, D.C. during President Trump's inauguration Jan. 20.

It was not clear if the DDoS attack was related to either website, and DreamHost did not immediately return an email Thursday seeking comment.