The hacking of Kan's website did not affect the regular television relay of the show on Tuesday night in Israel or abroad.
Hamas, the ruling party in the Gaza Strip, did not release any statement corroborating the accusation that they were behind the hacking. Earlier this month, Hamas engaged in three days of fighting with Israel that included hundreds of rocket attacks from Gaza and Israeli air strikes in the enclave.
Eurovision has faced immense pressure from pro-Palestinian groups over their decision to host the contest in Israel. After the 41-country competition kicked off on Tuesday with a first semi-final, Kan's webcast cut to animated satellite footage showing explosions in Tel Aviv set to a menacing soundtrack.
Kan played down the hack, noting that the evening ended without further incident as Greece, Belarus, Serbia, Cyprus, Estonia, Czech Republic, Australia, Iceland, San Marino and Slovenia made it through to Saturday's finals.
"We know that at a certain stage there was an attempt, apparently by Hamas, to commandeer our digital broadcast," Kan CEO, Eldad Koblenz, told Israel's Army Radio. "But I am happy to say that within a few minutes we managed to assume control over this phenomenon."
The popstar, Madonna, has also faced immense pressure from the Boycott, Divestment, and Sanctions (BDS) movement over her agreement to play at the Eurovision contest.
Rebuffing the pressure, Madonna said she would "never stop playing music to suit someone's political agenda".