In what Reshef said was a bid to tell subscribers what was happening, Blue Security pointed the company's corporate Web server URL to its blog, which is hosted by Six Apart Ltd. in San Francisco. PharmaMaster then launched a DDoS attack against the server hosting Blue Security's blog. That resulted in thousands of other blogs hosted by Six Apart to be knocked offline.

The DDoS attacks against the company's dedicated servers meanwhile resulted in service disruptions to five hosting providers and major DNS service provider Tucows Inc., he said.

Pointing the company's main URL to the Blue Security blog site on Six Apart when it was under attack may not have been the best idea, Reshef said. But at the time, the company had little idea that the attacker would launch a separate denial of service attack on the blog site as well.

Todd Underwood, chief operations and security officer at Renesys Inc., a Manchester, N.H.-based Internet monitoring company, said that based on traffic analysis, Blue Security's main Web site appears to have been under a DDoS attack for at least two days before it redirected its URL to the blog.

"I do think if you are under attack it is your duty not to redirect it against someone else," Underwood said. "It is not a fair or an ethical decision," he said, adding that it is hard to imagine that Blue Security didn't know it was being hit with a DDoS attack when it pointed its URL to the blog site.