I've got these all over my garden. When they're in bloom its a little white star flower. At first I thought they were cute, but now.... This is zone 5b

Looks like Star of Bethlehem, Ornithogalum umbellatum.

A little spot spray of round-up would probably get them under control.

Sadly, RoundUp will only kill the growth above ground I know because I have done several years of spraying (RoundUp for farmers - better product) and it did not kill them. You can set them back a few years by digging them up (note - they can go down a foot if they want to) and getting rid of all the little white bulbs (I put them in the garbage because they don't burn and don't 'drown/rot')

If you're still watching Wease48, here's a last thought - a weed is really only a plant growing where you don't want it so why not plant anemone blanda across your garden (the regular blue because the named white and large blue are probably sterile cvs) corydalis solida, scilla sibirica, muscari and mixed crocuses
You're stuck with the Ornithogalum so if you surround them with more desirable bulbs you may learn to live with them. The bulbs listed above have spread quite rapidly through my gardens - and I love them - but really they are still as invasive as Star of Bethlehem

I've had this spread in my yard. Oddly, right now I only find it right now Blooming in a couple shady places. So it is by far not my biggest problem plant.

And to think I deliberately purchase them every year. I scatter them in the lawn. They come up, bloom and are cut back when I mow. I'd rather them in the lawn instead of dandelion.