FIERCE(1)

NAME
fierce - DNS scanner that helps locate non-contiguous IP space and hostnames against specified domains.

SYNOPSIS
fierce [-h] [--domain DOMAIN] [--connect] [--wide] [--traverse NUMBER] [--search SEARCH [SEARCH ...]] [--range RANGE] [--delay DELAY] [--subdomains SUBDOMAINS [SUBDOMAINS ...] | --subdomain-file SUBDOMAIN_FILE] [--dns-servers DNS_SERVERS [DNS_SERVERS ...] | --dns-file DNS_FILE] [--tcp]

DESCRIPTION

Fierce is a semi-lightweight scanner that helps locate non-contiguous IP space and hostnames against specified domains. It's really meant as a pre-cursor to nmap, OpenVAS, nikto, etc, since all of those require that you already know what IP space you are looking for. This does not perform exploitation and does not scan the whole internet indiscriminately. It is meant specifically to locate likely targets both inside and outside a corporate network. Because it uses DNS primarily you will often find mis-configured networks that leak internal address space. That's especially useful in targeted malware. Originally written by RSnake along with others at http://ha.ckers.org/. This is simply a conversion to Python 3 to simplify and modernize the codebase.

OPTIONS
-h, --help
    show this help message and exit
--domain DOMAIN
    domain name to test
--connect
    attempt HTTP connection to non-RFC 1918 hosts
--wide
    scan entire class c of discovered records
--traverse NUMBER
    scan NUMBER IPs before and after discovered records. This respects Class C boundaries and won't enter adjacent subnets.
--search SEARCH [SEARCH ...]
    filter on these domains when expanding lookup
--range RANGE
    scan an internal IP range, use cidr notation
--delay DELAY
    time to wait between lookups
--subdomains SUBDOMAINS [SUBDOMAINS ...]
    use these subdomains
--subdomain-file SUBDOMAIN_FILE
    use subdomains specified in this file (one per line)
--dns-servers DNS_SERVERS [DNS_SERVERS ...]
    use these dns servers for reverse lookups
--dns-file DNS_FILE
    use dns servers specified in this file for reverse lookups (one per line)
--tcp
    use TCP instead of UDP

EXAMPLES

Something basic:
    $ fierce --domain google.com --subdomains accounts admin ads

Scan 10 IP addresses before and after discovered domains to find coniguous blocks using the `--traverse` flag:
    $ fierce --domain facebook.com --subdomains admin --traverse 10

Limit nearby IP traversal to certain domains with the `--search` flag:
    $ fierce --domain facebook.com --subdomains admin --search fb.com fb.net

Attempt an `HTTP` connection on domains discovered with the `--connect` flag:
    $ fierce --domain stackoverflow.com --subdomains mail --connect

Exchange speed for breadth with the `--wide` flag, which looks for nearby domains on all IPs of the [/24](https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#IPv4_CIDR_blocks) of a discovered domain:
    $ fierce --domain facebook.com --wide

Zone transfers are rare these days, but they give us the keys to the DNS castle. [zonetransfer.me](https://digi.ninja/projects/zonetransferme.php) is a very useful service for testing for and learning about zone transfers:
    $ fierce --domain zonetransfer.me

To save the results to a file for later use we can simply redirect output:
    $ fierce --domain zonetransfer.me > output.txt

Internal networks will often have large blocks of contiguous IP space assigned. We can scan those as well:
    $ fierce --dns-servers 10.0.0.1 --range 10.0.0.0/24