sec51 / honeymail

SMTP honeypot written in Golang

Status

The project is being actively developed.
This honeypot has been tested by Sec51 however we cannot guarantee that it's bug free!
Attackers may be able to gain access to your honeypot server in case of severe bugs.
Use at your own risk !
We are not responsible for any damages caused by this software.
For more information see the license.

SMTP honeypot

Here a list of features developed so far:

• Configurable response messages to avoid honeypot detection.
• Support for STARTTLS
• Support for TLS
• Storage of emails in a BoltDB file, separated by day.
• API to retrieve today's emails and specific email via its id. (API is under heavy development to add additional capabilities)
• Automatically extracts several information from the email, like: list of urls, source domain, country, attachments, email parts (HTML or TXT).
• Sha256 hash of email parts and fields like: FROM, TO, CC, attachments.
• API and allows to browse different days: /api/emails/today or /api/emails/YYYY-MM-dd
• Simple DDoS protection in case spammers try to establish many connections and never finish sending data.

Future development

• Process the attachments with YARA and Cuckoo to automatically create yara rules
• Create a web UI to visualize the stored information
• Improve the API and allow to retrieve an email via the SHA256 hash of its parts (TO, FROM etc...)
• Extract additional configuration parameters which are now hard coded (Example: amount of times a client needs to fail to send emails before it gets locked down)

How to run it:

1. Generate a public/private key via:

openssl req -newkey rsa:2048 -nodes -keyout smtp.key -x509 -days 365 -out smtp.crt

2. Move the newly created certificates to a cert folder.

3. Configure your remote ip address or ip address list in the conf/development.conf or conf/production.conf INI config file. This will allow only your IP to connect to the API. In addition set the path of the certificates.

4. Run the binary via:

setcap 'cap_net_bind_service=+ep' honeymail

5. Access the api via:

To see today's emails:

• /api/emails/today

To see a specific date emails:

• /api/emails/2010-07-30

To see a spefici email (you can find the id from the list return from /api/emails):

• /api/email?id=49689cfcb7fcbf83ed95df3a65ae6d9047678ca1

Please report any bugs you will encounter.

Dependencies

The project is now using go vendoring. So all dependencies are inside the vendor folder.

License

Copyright (c) 2016 Sec51.com [e-mail]

Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.