I's be suspicious that it is dripping down from the airbox.
The engine vents discharge into the airbox, and it is common for the bike to build up a little oil, especially if the engine is overfilled.
There is a drain hose that discharges near the right footpeg, that has a cap/plug in it. You need to check this a couple of times/year. You should also look into the airbox with a flashlight when you change the filter and see what is collecting in there.
I suspect you have a little oil collected and that it may be dripping down from where the drain hose connects to the airbox. This is the easiest thing to check first.