I bought a 26in dirt jumper/bmx bike. No markings but the guy said it was a fetish. The set up is bmx but the frame looks like a jumper. Bmx cranks and dropouts. The serial number is SNFSD13BF1725.
Fetish bikes are a white label brand out of Taiwan. Most of their bikes change year to year and rarely have any identifying markings to a model outside a sticker (which is not applied when shipped, leaving it optional for the first owner to apply).
Honestly it may not ever truly be identified. If you need a replacement part or repair, it's best to take it to a bike shop for the proper part analysis if you don't know what you are looking at.
This may be a Schwinn. I used the first 5 digits of the serial and plugged it into this stolen bikes registry website. There's a bike starting with a similar serial number also starting with SNFSD followed by the same number of characters: http://bikeindex.org/bikes/3836
Does the picture look like yours?