sub.Monitor

   Fast & user-friendly subdomain monitoring tool for continous attack surface management.

Why?

Why opt for sub.Monitor? This program offers easy setup due to its utilization of SQLite for storing all identified domains (removing the necessity for prior database management). Moreover, it boasts high customizability, with users needing to append only a few lines of code to the script using their chosen tools. In contrast to other existing solutions relying on databases such as MySQL or MongoDB, initializing the script can turn into a tedious task.

Features

• Fast
• Easy to use
• Easy to install
• Easy to customize
• Continuously save subdomains in the local database (with the possibility of dumping them all)
• Telegram/slack/discord notifications

Help Menu

sub.Monitor flags:

options:
  --add ADD             Domain to scan
  --out-scope OUT_SCOPE
                        File with out-of-scope domains
  --file FILE           File with known subdomains
  -D DOMAIN, --domain DOMAIN
                        Domain to scan
  -H HOURS, --hours HOURS
                        Hours between scans
  --dump                Dump all subdomains for a specific domain
  --list                List all root domains in the database
  -df DF                File with domains to scan
  --inscope             Dump only in-scope domains
  --notinscope          Dump only out-of-scope domains
  --dumpall             Dump all subdomains with their details
  --info                Show discovery date for subdomains
  -help, -?             Show this help message and exit

Previous needed configurations

You need to write the configuration (api) path files into config.ini file.

• Subfinder api configuration file.
• Amass api configuration file.
• Notify api configuration file.
• You will need to specify the binary and config paths on sub.monitor-config.ini file.
• Finally, execute pip3 install -r requirements.txt

You can easily implement your own tools on the script, just modify the lines of code:

def run_tool(tool, domain, output_file):
    print(f'[{datetime.datetime.now()}] - Running {tool} on {domain}')
    if tool == 'assetfinder':
        assetfinder_binary = config.get('Binary paths', 'assetfinder')
        cmd = f'echo {domain} | {assetfinder_binary} -subs-only | grep -E "{domain}$" |grep -v "*" | grep -v "@"'
    elif tool == 'subfinder':
        subfinder_binary = config.get('Binary paths', 'subfinder')
        subfinder_api = config.get('Api', 'subfinder_api')
        cmd = f'{subfinder_binary} -d {domain} -silent -pc {subfinder_api} -all'
    elif tool == 'amass':
        amass_binary = config.get('Binary paths', 'amass')
        amass_api = config.get('Api', 'amass_api')
        cmd = f'{amass_binary} enum -passive -norecursive -noalts -d {domain} -config {amass_api}'
    elif tool == 'my-custom-tool':
        my-custom-tool-binary = config.get('Binary paths', 'my-custom-tool-binary-or-script')
        cmd = f'{my-custom-tool-binary} -d {domain}'

It's important to note that if you add any custom tool, the last output must be the domain results in order to sub.Monitor save them on the database, for example the way of using it would be:

cmd = f'bash customtool.sh {domain}''
...
cat customtool.sh
mycustomtool -d $1 > /tmp/$1.txt &>/dev/null; cat /tmp/$1.txt | unfurl domains | anew; rm -r /tmp/$1.txt

Also add your tool name here:

                for tool in ['subfinder', 'amass', 'assetfinder', 'my-custom-tool-name']:
                    run_tool(tool, domain, output_file)

Finally, of course, you need to add the tool on the sub.monitor-config.ini file so that the python script can get the binary from that configuration file.

The only needed thing is that once the command is finished, it must show on the output all the domains discovered so the tool can save them on the logs file and inside the database

Work plan

First of all sub.Monitor needs a list of already scanned domains:

➜  cat ibm_sorted_subdomains.txt
test1.ibm.com
test2.ibm.com
test3.ibm.com
subtest.testX.ibm.com
...

Now, the file containing the subdomains can be passed to sub.Monitor with the following command:

python3 monitor.py --add ibm.com --file ibm_sorted_subdomains.txt
          _    ___  ___            _ _
          | |   |  \/  |           (_) |
 ___ _   _| |__ | .  . | ___  _ __  _| |_ ___  _ __
/ __| | | | '_ \| |\/| |/ _ \| '_ \| | __/ _ \| '__|
\__ \ |_| | |_) | |  | | (_) | | | | | || (_) | |
|___/\__,_|_.__/\_|  |_/\___/|_| |_|_|\__\___/|_|

                    github.com/e1abrador/sub.Monitor

[2023-06-06 18:16:26.002521] - 538 subdomains were added to the local database.

Also there is a possibility to add an out-of-scope flag, for example, let's say that a Bug Bounty program has the following policy:

*.ibm.com - in scope
super-admin.ibm.com - out of scope
*.super-admin.ibm.com - out of scope

It is possible to create a file with this stuff:

cat outscope.txt
super-admin.ibm.com
*.super-admin.ibm.com

Now, you can add manually all your discovered domains to the database (filtering the ones that are in scope):

python3 monitor.py --add ibm.com --file ibm_sorted_subdomains.txt --out-scope outscope.txt
          _    ___  ___            _ _
          | |   |  \/  |           (_) |
 ___ _   _| |__ | .  . | ___  _ __  _| |_ ___  _ __
/ __| | | | '_ \| |\/| |/ _ \| '_ \| | __/ _ \| '__|
\__ \ |_| | |_) | |  | | (_) | | | | | || (_) | |
|___/\__,_|_.__/\_|  |_/\___/|_| |_|_|\__\___/|_|

                    github.com/e1abrador/sub.Monitor

[2023-06-06 18:16:26.002521] - 538 subdomains were added to the local database.

This will add all your subdomains to the database, but it will mark all the ones that are out of scope with the flag [Out of scope] (we will see how to filter in-scope domains from the database on dumping domains section).

To confirm that the domain has been added to the database, execute:

python3 monitor.py --list
          _    ___  ___            _ _
          | |   |  \/  |           (_) |
 ___ _   _| |__ | .  . | ___  _ __  _| |_ ___  _ __
/ __| | | | '_ \| |\/| |/ _ \| '_ \| | __/ _ \| '__|
\__ \ |_| | |_) | |  | | (_) | | | | | || (_) | |
|___/\__,_|_.__/\_|  |_/\___/|_| |_|_|\__\___/|_|

                    github.com/e1abrador/sub.Monitor

ibm.com [9 subdomains added manually] [2 subdomains discovered] [11 total unique in database]

Once it has been correctly loaded, the monitoring process can start. It is recommended to use TMUX in a VPS and leave it running for a long time. With the following command, the script will be running the subdomain enumeration tools and will compare the new results with the old results. If there's any new subdomain found, sub.Monitor will first add it to the local database (so it will not notify anymore about that discovery) and then will notify the user via slack/telegram/discord.

python3 monitor.py -D ibm.com -H 12 --out-scope outscope.txt

If any subdomain is found, sub.Monitor will show the following message on the output:

➜ python3 monitor.py -D ibm.com -H 8 # To filter the subdomains that are in the current scope from the out-scope ones, you can use:
                                      # python3 monitor.py -D ibm.com -H 8 --out-scope outscope.txt

          _    ___  ___            _ _
          | |   |  \/  |           (_) |
 ___ _   _| |__ | .  . | ___  _ __  _| |_ ___  _ __
/ __| | | | '_ \| |\/| |/ _ \| '_ \| | __/ _ \| '__|
\__ \ |_| | |_) | |  | | (_) | | | | | || (_) | |
|___/\__,_|_.__/\_|  |_/\___/|_| |_|_|\__\___/|_|

                    github.com/e1abrador/sub.Monitor

[2023-06-06 18:07:25.191169] - New subdomain xxxx.ibm.com discovered
[2023-06-06 18:07:25.353156] - New subdomain xyxyxyxyxyx.ibm.com discovered
[2023-06-06 18:07:25.641082] - New subdomain x1.xxxx.ibm.com discovered

It is also possible to monitor more than 1 domain, with the following command:

python3 monitor.py -df root-domains.txt -H 8
python3 monitor.py -df roots.txt -H 8 --out-scope outscope.txt

After those messages are reported, on the same time the user will receive the notifications on telegram

How do I manage the notifications? I found a pretty easy (and easy to manage) way to see all newly discovered domains with Discord. I got this (blurred since all of them are private programs):

The idea is first to create a category regarding the program name:

> Yahoo

--- yahoo.com

--- yahoo.net

--- etc ...

> IBM

--- ibm.com

--- whateverdomain.com

--- etc ...

This is what my notify config file looks like:

I recommend doing this for each domain (it may be pretty tedious to set up this but it is a great way to manage the results). monitor.py script will send the results to the given webhook based on the ID (which must be the same as the domain name to scan).

Let's say that the script has been running for 2 months and you want to get all the results (old subdomains and newly discovered ones). With sub.Monitor whether it is possible using the --dump flag:

python3 monitor.py -D ibm.com --dump

          _    ___  ___            _ _
          | |   |  \/  |           (_) |
 ___ _   _| |__ | .  . | ___  _ __  _| |_ ___  _ __
/ __| | | | '_ \| |\/| |/ _ \| '_ \| | __/ _ \| '__|
\__ \ |_| | |_) | |  | | (_) | | | | | || (_) | |
|___/\__,_|_.__/\_|  |_/\___/|_| |_|_|\__\___/|_|

                    github.com/e1abrador/sub.Monitor

Subdomains for ibm.com:
subdomain1.ibm.com
subdomain2.ibm.com
...

You can also use the following command to see the day on which the domain was discovered:

python3 monitor.py -D ibm.com --dump --info

          _    ___  ___            _ _
          | |   |  \/  |           (_) |
 ___ _   _| |__ | .  . | ___  _ __  _| |_ ___  _ __
/ __| | | | '_ \| |\/| |/ _ \| '_ \| | __/ _ \| '__|
\__ \ |_| | |_) | |  | | (_) | | | | | || (_) | |
|___/\__,_|_.__/\_|  |_/\___/|_| |_|_|\__\___/|_|

                    github.com/e1abrador/sub.Monitor

Subdomains for ibm.com:
test.ibm.com [discovered on 06/08/2023]
test2.ibm.com [discovered on 08/08/2023] [Out of scope]

As it's highly probable that some domains are marked as out of scope using python3 monitor.py -d ibm.com --dump --info command, in order to show only the domains in-scope it is possible to use --inscope flag:

python3 monitor.py -D ibm.com --dump --info --inscope

          _    ___  ___            _ _
          | |   |  \/  |           (_) |
 ___ _   _| |__ | .  . | ___  _ __  _| |_ ___  _ __
/ __| | | | '_ \| |\/| |/ _ \| '_ \| | __/ _ \| '__|
\__ \ |_| | |_) | |  | | (_) | | | | | || (_) | |
|___/\__,_|_.__/\_|  |_/\___/|_| |_|_|\__\___/|_|

                    github.com/e1abrador/sub.Monitor

Subdomains for ibm.com:
test.ibm.com [discovered on 06/08/2023]
test3.ibm.com [discovered on 08/08/2023]

Thanks

Thanks to:

• Projectdiscovery for creating subfinder and notify!.
• Thanks to OWASP for their amazing project amass!.
• Tomnomnom for creating assetfinder!.

TODO

• Implement the monitoring of more than 1 subdomain. [DONE]
• Continuously read the domain files so new domains can be scanned without stopping the program. [DONE]
• Implement out of scope filtering [DONE]

If you have any idea of some new functionality open a PR at https://github.com/e1abrador/sub.Monitor/pulls.

Good luck and good hunting! If you really love the tool (or any others), or they helped you find an awesome bounty, consider BUYING ME A COFFEE! ☕ (I could use the caffeine!)

⚪ e1abrador

Twitter: https://twitter.com/e1abrador