After Newsweek published a report titled "How Donald Trump's Company Violated The United States Embargo Against Cuba," the site found itself on the receiving end of a "massive" denial-of-service attack that managed to shut down the site for several hours. TPM reports: Editor-In-Chief Jim Impoco noted that the attack came as the story earned national attention. "Last night we were on the receiving end of what our IT chief called a 'massive' DoS (denial of service) attack," Impoco wrote in an email to TPM. "The site was down most of last evening, at a time when Kurt Eichenwald's story detailing how Donald Trump's company broke the law by violating the U.S. trade embargo against Cuba was being covered extensively by prominent cable news programs. Our IT team is still investigating the hack." Later Friday afternoon, Impoco emailed TPM that in an initial investigation, the "main" IP addresses linked to the attack were found to be Russian. It should be noted that it is possible to fake an IP address. "As with any DDoS attack, there are lots of IP addresses, but the main ones are Russian, though that in itself does not prove anything," he wrote. "We are still investigating." Eichenwald tweeted Friday morning: "News: The reason ppl couldnt read #TrumpInCuba piece late yesterday is that hackers launched a major attack on Newsweek after it was posted."