Splitting the Usage Details

python 3 altdns -i target_subdomains.txt -o result_data_output -w possible_words.txt -r -s results_output.txt

1. target_subdomains.txt – This file includes the list of subdomains of the organization
2. result_data_output – This file will include the massive list of altered and permuted subdomains after the scan is completed.
3. results_output.txt – This file will include the final list of permuted subdomains found that are valid and have a DNS record.
4. possible_words.txt – This is the by default file in the altdns directory, which includes the dataset of words you’d like to permute your current subdomains.
5. -r flag – This flag resolves every generated, permuted subdomain
6. -s flag – This flag helps altdns in saving the results of the resolved permuted subdomains. results_output.txt will contain a final list of altered subdomains found that are valid and have a DNS record.
7. -t flag – This flag limit the threads the resolver will use parallelly.
8. -d flag – This flag revokes the system default DNS resolver and will use the specified IP address as the resolving server.

Subdomain Enumeration is the non-negligible step of Penetration Testing. Every Tester has to Enumerate Subdomains for different phases. Several scripts are automated to find subdomains of the specified target, but Altdns is a superb security tool that can discover and explore subdomains. Altdns is a python script or python language-based tool. Altdns has the feature to generate permutation, alteration, and mutations of subdomains of the specified target domain. The Tester can use these generated names for DNS lookups. Altdns is an open-source tool and free to use. Altdns tool works efficiently in the phases of Information gathering, Reconnaissance subdomains, and finding subdomains from even HTTPS secured websites.  Altdns tool generates two lists of subdomains as a result. The 1st list is a collection of identified subdomains, and the 2nd list s the group of possible words used as a subdomain like testing, status backup, etc.

Note: Make Sure You have Python Installed on your System, as this is python-based tool. For more information, refer to the article Python Installation Steps on Linux