title: How can I know if a decompiled APK is obfuscated?
body: <p>I am checking an APK for obfuscation within it's components code, but I'm not sure if it was in fact implemented.</p>
  
  <p>How can I know for sure if they are protecting their APK's code through obfuscation? As in what procedure should I follow and what elements will make me notice if they are or not? Is there a way to know just by looking at the decompiled code if ProGuard, DexGuard or some other obfuscation technique is in place?</p>
  
  <p>I know obfuscating is mostly security through obscurity, this is just one of the things I'm checking.</p>
  
  <p>I've decompiled the APK with both a webservice and apktool, obtaining different results, ie. for a particular folder, its subfolders appear as a,b,c in the one decompiled by apktool but appear with other names (as p00xxxx) in the folder output from the web service.</p>
  
  <p>Also:</p>
  
  <ul>
  <li>Method and field names appear as a,ab,ac,v0,v1,etc.</li>
  <li>When greping for 'user','usuario','password' or 'contraseña' the only
  instances of these strings are in xml 'name' tag attributes and in
  literal strings such as "please enter your password". These
  tags ids' are in the form of: 'aXaaaaaaaa'. This seems to me like a proof of obfuscation. As posed <a href="https://samsclass.info/128/proj/p10-proguard.htm" rel="nofollow noreferrer">here</a> (under the 'Search for password' title). </li>
  <li>It seems possible to me for DexGuard to be implemented, as the
  code I've revised looks a lot like the examples portrayed <a href="http://ftp.icm.edu.pl/packages/Hacked%20Team.git/core-android/RCSAndroid/antlibs/historic/DexGuard5.5.72/docs/examples.html#repackaging" rel="nofollow noreferrer">here</a>
  ('Obfuscating Package Names')</li>
  </ul>
  
  <p>I also read somewhere that the presence of goto instructions may  indicate obfuscation, is this right?</p>
  
  <p>To sum up, I just want to know if there is a way for me to know if the APK was obfuscated, what should I do in order to check this, and what signs should I be looking for. I will really appreciate any help.</p>