Pretty sure that's fungus.
It hasn't spread too much yet though, you might aswell have a go at pulling it apart and cleaning it off. Especially if it was a cheap purchase. A camera repair shop could sort it out for you too.
Not sure what your lens cleaner will be composed of, but try getting some isopropyl alcohol and some good cloths. If you need something stronger than that to clean it off, you can try acetone. However with the acetone, avoid breathing in the fumes as much as possible
It looks like the fungus is just on the front element but it's hard to say. If it's just confined to the front element it may be quite easy to get to and clean. But you wont know until you pull it apart
If you just leave it as is, Denis (creampuff) is right, it will just get worse. And yeah the longer it's there the greater the risk of lens coating damage.
A lens with any fungus has very little sale value.