Cатсн²² (in)sесuяitу / ChrisJohnRiley

Because we're damned if we do, and we're damned if we don't!

BSidesLV: Android Backup [un]packer release

bsideslvlogoAs part of my “Mobile Fail: Cracking open “secure” android containers” talk at BSidesLV I’ve released a couple of scripts I wrote to automate some of the legwork involved in backing up Android applications and automatically unpacking their data and settings. The accompanying script takes the data and settings structure and re-packs it into a working Android Backup file for restoration.

These scripts were used as part of my research to view settings used by applications and in some cases alter the configuration to deactivate secure features or allow access. In some cases it’s also possible to alter configuration files to gain elevated functionality (unpaid… but nobody would ever do that… right!).

The process isn’t new and can be done manually, however automated solutions are always easier…

packer unpacker


  • openssl with zlib support
  • star (apt-get install star)

Simple Python scripts to perform:

  • an adb backup of a specific application and uncompress it to a directory structure
  • recompress a directory structure back into a valid adb restore file

Example usage:

./ab_unpacker.py -p com.app.android -b app.ab

  • Creates an adb backup of com.app.android called app.ab and uncompresses it into ./com.app.android

./ab_packer.py -d ./com.app.android -b app_edit.ab -o app.ab -r

  • Repacks the contents of ./com.app.android into app_new.ab and attempts to restore it via adb




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