QARK - Free Android App Scanner to find Security Vulnerabilities

QARK (Quick Android Review Kit) is a free Android app scanner to find security vulnerabilities. This tool is able to extract the source code from apk file and list out security vulnerabilities. This tool is not a comprehensive tool but surely it is one of the tools to provide some good observations and issues for Android mobile apk.

Vulnerabilities related to exported components, intents, improper x.509 certificate validation, configuration related to files, activities, private keys embedded in the source, cryptography-related issues, WebView configurations, activities, Tapjacking, etc. have been found by using this tool.

How to Install QARK on Linux-based OS

Download the installer by using the below command

$git clone https://github.com/linkedin/qark

$cd qark

$pip install -r requirements.txt

$pip install . --user

To check whether the installation is proper or not

$qark

Usage

qark --apk <PATH-OF-APK-FILE>

I have used test mobile apk to run the scan to find a few security issues. "goatdroid.apk" is a test application available in "tests" directory.

Default report format is html type and you can open it on any browser.

While starting a security scan for apk file, I encountered the below error:

$qark --apk test.apk

Failed to extract zipped APK from /home/ubuntu/proj1/test.apk to /home/ubuntu/qark/build/qark
Traceback (most recent call last):
  File "/home/ubuntu/.local/lib/python2.7/site-packages/qark/decompiler/decompiler.py", line 228, in unzip_file
    zipped_apk.extractall(path=destination_to_unzip)
  File "/usr/lib/python2.7/zipfile.py", line 1063, in extractall
    self.extract(zipinfo, path, pwd)
  File "/usr/lib/python2.7/zipfile.py", line 1051, in extract
    return self._extract_member(member, path, pwd)
  File "/usr/lib/python2.7/zipfile.py", line 1106, in _extract_member
    file(targetpath, "wb") as target:
IOError: [Errno 13] Permission denied: '/home/ubuntu/qark/build/qark/AndroidManifest.xml'
Failed to extract zipped APK

This issue has been resolved by run that command using sudo, but other error has come

$sudo qark --apk test.apk

Decompiling...
/home/ubuntu/.local/lib/python2.7/site-packages/qark/decompiler/../lib/dex2jar-2.0/d2j_invoke.sh: 48: /home/ubuntu/.local/lib/python2.7/site-packages/qark/decompiler/../lib/dex2jar-2.0/d2j_invoke.sh: java: not found
Error running dex2jar command: /home/ubuntu/.local/lib/python2.7/site-packages/qark/decompiler/../lib/dex2jar-2.0/d2j-dex2jar.sh /home/ubuntu/qark/build/qark/classes.dex -o /home/ubuntu/qark/build/qark/test.jar
Error running dex2jar

The above issue is resolved just by installing openjdk

$sudo apt install openjdk-8-jre-headless

Conclusion

QARK is an awesome tool to start Android app security. This tool test specific security issues in the mobile app. As told in the beginning, you can use other tools also for static and dynamic analysis of mobile apps.