Web site host and domain name registrar Register.com has been the target of a sustained attack this week, disrupting service for thousands of customers.
The attacks began on Wednesday, causing a three-hour outage for many Web sites that rely on the company for hosting and/or use the company's domain name system (DNS) servers, said Roni Jacobson, executive vice president at Register.com.
The outage was the result of what's known as a distributed denial of service (DDoS) attack, in which attackers cause hundreds or thousands of compromised PCs to flood a target with so much junk traffic that the Web site can no longer accommodate legitimate visitors. Typically, DDoS attacks are waged as a way for criminals to extort money from the targets, who are told the attack will cease when a ransom demand is paid.
Jacobson declined to say whether Register.com had received any extortion demands.
"We did have a flooding of traffic to portions of our system which impacted services to customers and was restored as quickly as possible," Jacobson told Security Fix on Thursday.
The attack appeared to persist until at least Friday, when Register.com chief executive Larry Kutscher sent an apologetic message to customers via e-mail.
Earlier today we communicated to you we were experiencing intermittent service disruptions as a result of a distributed denial of service (DDoS) attack - an intentionally malicious flooding of our systems from various points across the internet.
Services have been restored for most of our customers including hosting and email. However for some of our customers, services are not fully restored. We know this is unacceptable.
We are using all available means to restore services to every one of our customers and halt this criminal attack on our business and our customers' business. We are working round the clock to make that happen.
That may have been too little, too late for some customers. John Ketchpaw, co-owner of panopto.com, said he opted to move his company's site hosting to another provider due to the disruptions, which blocked customers from accessing his site most of the day on Wednesday.
Ketchpaw said his company wasn't even able to receive e-mail, because its e-mail servers also relied on Register.com's DNS servers.
"This was sort of the last straw for us," Ketchpaw said. "Our whole company was offline pretty much all day, and everything just came to a screeching halt."
Register.com is the eighth largest domain registrar, with roughly 2.7 million domains, according to registrarstats.com.