Looks like a dirty No-toil filter and oil next to it. Use the No-toil cleaner, trust me on this one. I'm not pushing the product, but if that's the brand of filter oil in it, the same brand cleaner is about the only thing that'll easily clean it.
After 10 cleanings my No-toil filters still look like new. I just replace them because they start to get a little flimsy. Using the matching cleaner gives you a clean filter in seconds, and the sticky oil comes right off your hands.
It's safe for your drains too, I clean mine in the kitchen sink. Just go get some, put your filter in a bucket with water and some cleaner, rinse, and you'll be amazed how quickly the filter comes clean. No stickiness either.