The malware detector on my Galaxy S4 (4.4.4) reports a bit of advertising malware (Adware.Mobclick) exists on the phone's external SD card; that's the only place any malware is present on the phone. Using ASTRO file app, I can find the offending file. But I can't remove it: Google (or somebody) doesn't let the phone "write to an external SD card." So, how do I get rid of it? (Or is it harmless where it is??)