F3344.cn is an adware website, that is capable of redirecting the current browser into other malicious Web pages. It's related to another two websites, "pop.yeachi.cn" and "pop.jxz5.com". It's a Chinese website. It's known for being a carrier of the YeaDesktop malware, other than being a carrier of various adware trojans (especially of the ChinAd family).
When it is visited, it will make the user's browser display unwanted advertisements which will slow down the user's computer.
AdwCleaner and Malwarebytes are capable of doing a complete removal.