...only a "small number of groups" in the world have the sophistication necessary to execute an attack to take out the Drudge Report for extended periods of time.

"I would say it would be a group or nation-state that has pretty sophisticated methods and means," he said. "Given the fact it's happened a number of times and is persistent for well over a few minutes, and it's coming from multiple sources, against a site that would have a lot of protection, it would indicate it's someone pretty sophisticated."

Chris Weber, co-founder of the firm Casaba Security, explained that because the Drudge Report is "getting so much traffic already," a DDoS attack would need to be on a far "greater magnitude" to be effective against it.

"It does seem unlikely that the Drudge Report would be easily taken down or slowed significantly by a standard DDoS attack," he said. He surmised that the attack that took down the website was perhaps more on the scale of the massive cyberattack that temporarily knocked out Dyn, a large DNS company, in October 2016. WikiLeaks said its supporters were behind that attack as a show of support for the group's founder, Julian Assange.

Outside nation-states, it is equally probable that the Drudge Report has come under fire from a "hacktivist" organization, perhaps unhappy with the political views espoused by its founder.

Drudge has always been a controversial conservative figure, but in 2016 he went all-in for President-elect Donald Trump, often igniting controversy with inflammatory headlines emblazoned on his website.

But hacktivist organizations almost always take credit after a successful attack has been executed, experts said. So far, no one has claimed credit for the attacks on the Drudge Report.

And, without a group taking credit, it may be impossible to determine the culprit....