An NBC reporter's stunned reaction during the White House shooting scare is going massively viral ... with social media users already turning the moment into memes.

NBC News correspondent Julie Tsirkin was filming outside the White House Saturday when multiple gunshots suddenly rang out nearby. In the now-viral clip, Tsirkin freezes mid-report and asks, "What is that?" as loud pops echo through the area behind her.

Her cameraman initially guessed the sounds were fireworks ... but seconds later, the seriousness of the situation became obvious as Tsirkin and her crew rushed toward cover while an armed Secret Service agent moved into position outside.

Online, many users started reacting to the clip with Cardi B's famous "Oh my God, what is that?!" meme GIF ... joking Tsirkin's confused reaction instantly reminded them of the viral moment. Countless others have chimed in on the moment, too.

As we reported ... according to authorities, Nasire Best allegedly approached a White House checkpoint Saturday evening and opened fire after pulling a gun from a bag. A bystander was injured before Secret Service agents returned fire and killed Best at the scene.

ABC News correspondent Selina Wang was also outside during the chaos and shared footage from the White House lawn, saying it sounded like "dozens of gunshots."