Illustrative. Photo: Zoom.

Worshipers who attended an online Shabbat service held by a synagogue in Connecticut last Friday night were briefly subjected to a “Zoom-bombing” by antisemitic hackers who filled the screen with swastikas, the congregation’s rabbi disclosed on Monday.

The hack lasted about three seconds, “but it was three seconds too long,” Rabbi Jeffrey Bennett of the Temple Sinai congregation told the Hartford Courant on Monday.

The intrusion came during Mourner’s Kaddish, a remembrance of loved ones who have died, as about 200 congregation members watched on Zoom and Facebook Live, Bennett told the Courant.

The hackers used the “annotate” feature offered by online platform Zoom to post swastikas on the shared screen. They also used the audio feature to play klezmer music as a mockery and the chat feature to write inappropriate messages for all to see, according to service participants.

Bennett quickly stopped sharing his screen and a worship service co-host muted all attendees, the temple board of directors wrote in a notice to congregants. The service then continued without incident.

Temple leaders filed an incident report with the Anti-Defamation League (ADL) and sent a message to the Zoom security mailbox outlining the breach. Local police also were alerted and said they would boost patrols around the synagogue’s building.