Is this mold or something else

I really don't have time to write a good answer, but I have and others have written some good responses that would answer your question. Look at the tags for mold. ID is important before remediation can be done. You have to know what kind of mold you are dealing with. Some minor mold can be dealt with DIY, but other toxic molds need professional attention. Samples need to be taken and IDed by a lab. Don't take chances, get it right.

Yes, it's mold. This happened in my apartment after an extended stay away from home during the summer. I used plain old soap and water and it has worked for me. I had no problems doing it this way. There is no way to indefinitely get rid of all the mold (you will inevitably leave some mold spores behind) as long as there is enough moisture in the air.

There are many ways to prevent mold growth. I bought a dehumidifier and it seems to have done the trick. I have not had any mold since. No mold will grow without moisture. Get rid of the moisture and you will get rid of the mold.

Update
I found an article that does a good job explaining how to get rid of mold.