There's a "CopyCat App" that is identified as "a.frau.longjian.a" and appears to Android users as an update of the popular NetDragon 91 Assistant app. If you download this update, it will download repackaged apps that would hide in the background and use up your data.
How does it use up your data? It will automatically subscribe you to paid SMS services which would rack up the phone bills. It also breaches your security by sending sensitive and personal information of your phone such as IMEI and other phone details, numbers and app usage. More info on this fraudware is available here
I don't usually have an antivirus on but this would be a good reason why. There's not really much chance for me to get the update but it can be scary if I get careless just once.