Scary moment on the streets of Paris just a few miles from Kim Kardashian testifying in the jewelry heist trial ... the daughter of a cryptocurrency CEO and her toddler were attacked by a group of would-be kidnappers who tried to stuff them into the back of a van in broad daylight ... it's all on video, and now cops are investigating.

Footage shows a group of masked men trying to force the woman into a van as she screams for help and her baby daddy shields their child with his body ... taking multiple blows.