Do you ever take a look at your footage in the edit room and find out there are specks on it? Sometimes it’s due to a dirty lens, other times there might be dust that has gotten on the sensor inside your camera. Either way there are methods to remove it in post using After Effects. This guy from Filmmaker IQ goes through this process for your edification and enlightenment.
I did not use this method exactly, but I did use the principals here to modify my own color mask and cover a bug that had flown onto my lens and proceeded to walk around on it. I can post the results later upon request.
Thanks for reading!