If you need to modify or inspect APKs, use transparent, open-source tools:
Simply downloading a file is generally safe; the risk only begins once you manually grant permission to install it from "Unknown Sources". base8apk
Base8APK can unpack an APK into smali code (a human-readable assembly-like representation of Dalvik bytecode), resources, and the AndroidManifest.xml file. If you need to modify or inspect APKs,