About DNSkron

DNSkron is a Linux shell script developed to enumerate historical DNS records, subdomains, analyze network infrastructure and find potentially related websites for a target domain or IP address. In some situations helps to disclosure Cloudflare protected websites. The script uses Virustotal free API key

Requirements

DNSkron requires curl, csvtool, jq

$ sudo apt install curl csvtool jq

Installation

1. Register a Virustotal account and get your free API key
2. Download dnskron.sh to your Linux PC and put it into a folder
3. Install requirements
4. Open dnskron.sh with a text editor, replace <API_KEY> (line 7) with your API key and save the file

Usage

Open Terminal in a folder where the script is located and type the following (root rights are not required):

$ bash dnskron.sh

Example:

• For a target domain "free-mp3-radio.fm" we will create a "free-mp3-radio" case and use key words "mp3, radio, fm, music", they will help us to find related domains (can be operated by the same owner).

In addition to stdout output the script creates a folder with a csv file with all IP addresses found and a txt file with subdomains and IP related information. Timestamp shows when domain was seen on that IP for the last time.

API limit is enough for a non-commercial daily use (1000 queries). Amount of domains resolved from IP is limited to 1000. The script was tested on Ubuntu/Debian systems.

Hint: Set scrolling in terminal to unlimited, the output may include thousands of domains.

License

free

Special thanks to Virustotal: Guys you are doing a great job!!!

Screenshots

Issues and code updates

1. Incorrect display of subdomains list in summary - SOLVED (26.11.2020)
2. Logical mistake causing problem with the IP list (unique IPs) - SOLVED (28.11.2020)