One of the biggest annoyances for UC users is when attempting to download a file and being forcibly redirected to the Google Play Store or an app-update page. The handler injects a script that blocks these redirects.
The "uc handler 98 apk" falls into the category of "Greyware" or potentially unwanted programs (PUPs). While it may promise free internet or unlocked features, it presents a severe threat to user data privacy and device integrity.