Eric Tabach, an actor and YouTuber, messaged his friend Christian Nilsson in May with an intriguing question: With virtually every theater shuttered during the coronavirus pandemic, could they top the box office if they somehow released a new movie?

Nilsson, a New York-based filmmaker, hatched a plan. Now, just a month later, the former BuzzFeed colleagues have joined the ranks of Steven Spielberg, James Cameron and Christopher Nolan with a box-office-topping movie to their names.

With an official haul of $25,488, their 29-minute horror flick “Unsubscribe” — shot at no cost and entirely on Zoom — led the national charts on June 10, according to Box Office Mojo, among the industry’s premier revenue trackers.

“In any other climate, this would be impossible,” Nilsson, 32, told The Washington Post with a laugh on Wednesday night. “A year ago right now, ‘The Secret Life of Pets 2’ was No. 1,” and eventually made $430 million.

Okay, so Nilsson and Tabach used a giant loophole to pull it off. Their movie hasn’t actually made any real money yet.

But the tale of how they etched their names into cinematic history is a testament to artistic ingenuity under lockdown and, someday, could become an enduring reminder of just how bizarre this year has been for every aspect of American life.

As Tabach tells it in a behind-the-scenes video on the making of “Unsubscribe,” he was desperate for a creative project during a quarantine that has ground Hollywood to a total halt. When he pitched Nilsson on the idea of somehow releasing a new movie, the filmmaker immediately thought of a way to game the box-office system.

“There’s this thing in the industry called ‘four-walling,’ where if you rent out your own theater, the revenue from any ticket purchased goes straight back into your pocket,” Nilsson said.

Normally, with blockbusters hauling in millions every weekend, there’s no way that “four-walling” a project could come close to cracking box-office numbers. But with theaters closed, Hollywood has been releasing major films straight to streaming. Lately, tiny movies screened on a few drive-in theaters have topped the charts with just a few thousand dollars in revenue.

So the pair got to work. They decided quickly they wanted to make a real movie.

“We could have just filmed ourselves singing, ‘Happy Birthday,’ and this technically would have worked,” Nilsson said. “But we set out to create something that YouTubers would connect with. We wanted a film that’s really baked into that YouTube world of commenters and trolls.”

Nilsson wrote the script on May 9 in one day, crafting a story of a twisted online commenter who tricks famous YouTubers into a Zoom call and then stalks them on camera.

Tabach, a former viral video producer at BuzzFeed, got to work recruiting. He landed some real talent. Charlie Tahan, who plays the killer, is well known for his recurring role as Wyatt Langmore on “Ozark,” and co-star Michelle Khare has an upcoming series on HBO Max. He also bagged big-name YouTubers like Zach Kornfeld of “The Try Guys” and Thomas Brag of “Yes Theory,” each with millions of subscribers.

Stewing at home, everyone was eager — even if they didn’t quite believe the ultimate aim for the project.

“Everyone was available, obviously,” Nilsson said. “When we pitched the project and they heard we were trying to make it the number one movie in America, I don’t think they believed me. Some didn’t even think this was a real thing.”

They filmed the project in a week in mid-May, with all the actors performing remotely on Zoom. After a few weeks of editing and working with a composer on an original score, “Unsubscribe” was ready to screen.

Nilsson got in touch with an independent cinema in Westhampton Beach, N.Y., where he used to work, and agreed to rent out the shuttered space for one day for a “very small number,” Nilsson said.

Nilsson and Tabach showed up in tuxedos and sat munching popcorn by themselves in the empty theater as the movie played three times — enough screenings to “generate” more than $20,000 in revenue, under the “four-walling” rules.

It wasn’t actually easy to convince the box-office counters that the film was legit, though. IMDb, which runs Box Office Mojo, refused to believe they’d actually cast actors like Tahan in the film.

“They kept rejecting us,” Nilsson said. “Eventually, we shared the full film and the photos of every single person in the movie, and they finally verified that it was the No. 1 movie in America on that date.”

That box-office “record” may just be a quirk of pandemic history, but real viewers can now rent “Unsubscribe” through Vimeo. And Nilsson said he hopes the stunt will inspire other moviemakers in the age of coronavirus.

“Filmmakers are trying to find ways to move forward while being conscious of covid restrictions. It’s really important we find ways to make that work safely,” Nilsson said. “As silly as this project is, we achieved that.”