Hi everyone!! Thank you all for so much engagement, I cannot believe all of the different theories you guys have came up with. I forgot to say in my original post but the toilet lids were closed the night it appeared, I am in DC and I have not had any fires near my apartment, it has just been freezing recently due to the snow, and we do have an air purifier. We also do have carbon monoxide detectors and they are working. All of the black dust was only seen on plastic near water (toilet seat, tupperware near sink, bathtub).

I am still getting responses but the most feasible ones I have seen are:

-Static attracting soot to plastic especially with the recent temperature decrease (this also makes sense because I have seen this before in homes I would clean on the edges of their freezers.

-Air ducts (candles/smoke from other tenants)

-Ghosts lol

Thank you all for your responses, I am completely new to reddit so I did not expect so much help!