MASC : A Web Malware Scanner

MASC is a malware (web) scanner developed during CyperCamp Hackathon 2017. At the moment, there are some features available for any type of website (custom or CMS) and some of them only available for specific platforms:

• Scan any website for malware using OWASP WebMalwareScanner checksum, YARA rules databases and ClamAV engine (if available)
• Perform some cleaning operations to improve website protection
• Monitor the website for changes. Details are written in a log file
• Scan your site to know if it has been infected with some malware
• List your local backups
• Logging support
• Backup your site
• Restore website
• Scan for suspect files and compare with a clean installation (for WordPress and Drupal)
• Clean up your site to avoid giving extra information to attackers (only available for WordPress)

Also Read – MIG : Distributed & Real Time Digital Forensics At The Speed Of The Cloud

Requirements

First of all, notice that this tool is developed under Linux and, at the moment, it has been tested only under this Operating System

• Python >= 3
• Some Python libraries
  • python-magic
  • yara-python
  • watchdog
  • termcolor
  • pypandoc
  • progress

santi@zenbook:$ pip3 install python-magic yara-python watchdog termcolor pypandoc progress

• ClamAV to integrate with its engine (optional but recommended)

Notice

In my notebook, after upgrading to Debian testing, masc became to show an error related to Yara

OSError: /usr/lib/libyara.so: cannot open shared object file: No such file or directory

After trying a lot of solutions I found in the Internet, I realized that this file was located in my computer in/usr/local/lib/python3.5/dist-packages/usr/lib, so I created a symbolic link from the previous path to /usr/lib

santi@zenbook:$ ln -s /usr/local/lib/python3.5/dist-packages/usr/lib/libyara.so /usr/lib/libyara.so

And now, masc and Yara library are running with no problems.

Notice

masc is developed under Linux and it has not been tested under any other Operating System.

Anyway, it should run without problems under any Unix-friendly OS. In particular, in Mac OSX I have noticed it’s neccesary to install Homebrew to use python-magic library propery as libmagic. Check first the previous link to the brew homepage and then you will be able to install as I show below:

santi@zenbook:$ brew install libmagic

Also, in my computer I had to change the first line of the masc.py script. Python3 is installed in /usr/local/bin and it’s not allowed to create symlinks from /usr/bin

Change the first line in masc.py

#!/usr/bin/python3

for this line

#!/usr/local/bin/python3

Anyway, you always can run masc using the Python interpreter instead running the script directly:

santi@zenbook:$ python3 masc.py

Installation

To install masc on your computer, you can download a release, untar it and try. You can also install it usign pip (‘pip3 install masc’)

Check this notice before if you are using Mac OSX.

Usage

masc 0.2.2 (http://github.com/sfaci/masc)
usage: masc.py [-h] [–add-file FILENAME] [–add-word STRING] [–clean-cache]
[–clean-site] [–list-backups] [–make-backup] [–monitor]
[–name NAME] [–path PATH] [–rollback] [–scan]
[–site-type {wordpress,drupal,custom}]

optional arguments:
-h, –help show this help message and exit
–add-file FILENAME Add a suspect file to the dictionary
–add-word STRING Add a suspect content to the dictionary
–clean-cache Clean masc cache (cache and logs files, NO backups)
–clean-site Clean up the site (and apply some extra actions to hide information to attackers)
–list-backups List local backups
–make-backup Create a local backup of the current installation
–monitor Monitor site to detect changes
–name NAME Name assigned to the scanned installation
–path PATH Website installation path
–rollback Restore a local backup
–scan Scan website for malware
–site-type {wordpress,drupal,custom}
which type of web you want to scan:: wordpress,
joomla, drupal or magento

The actions you can perform over a web installation are:

• –scan (with or without the option –clean-site)
• –rollback
• –monitor
• –make-backup

And you have to consider that if you want to perform some actions over some kind of web installation, it’s mandatory to specify the type (-t or –type) and path (-o or –path).

For instance, if you have a WordPress installation in /var/www/html and you want to scan it entirely:

santi@zenbook:$ ./masc.py –scan –type wordpress –path /var/www/html

And if you want to perform clean up actions (to remove some malware, for instance):

santi@zenbook:$ ./masc.py –scan –type wordpress –path /var/www/html –clean-site

Credit: Santiago Faci