This post contains various commands and methods for performing passive recon of a target. This article will be expanded upon as time goes on.

Performing Whois lookups

We can utilize public WHOIS databases to perform lookups on domains.
https://lookup.icann.org/

It may also be worthwhile utilizing other services, such as Namecheap. Once you know who the registrar is, it is typically best to perform a Whois lookup for your target using their domain registrar.
https://www.namecheap.com/domains/whois/

We can also utilize a Kali terminal for this:
whois <targetDomain>

You can use additional options to instruct the tool to use a different server.
whois -h whois.godaddy.com <targetDomain>

Performing DNS enumeration with Nslookup

To perform a lookup of the A records against a particular domain:
nslookup <targetDomain>

To look up the mail records:
nslookup -query=mx <targetDomain>

To look up Nameservers:
nslookup -query=ns <targetDomain>

To get all records that are available:
nslookup -query=any <targetDomain>

You can also drop into nslookup with no parameters interactively.
nslookup

While interactively working with nslookup, you can set your query:
set q=mx

You can also set your server if you wanted to query a different DNS server than your default one:
server 8.8.8.8

Performing DNS enumeration with Dig

To extract A records and Namerservers of a domain:
dig <targetDomain>

To query just A records:
dig <targetDomain> A

You can also limit the output to a specific record, and just return the answer section:
dig +nocmd <targetDomain> MX +noall +answer

Can attempt a DNS Zone transfer:
dig +nocmd <targetDomain> AXFR +noall +answer @<targetDNSServer>

To see more about a DNS Zone Transfer, see https://infinitelogins.com/2020/04/23/performing-dns-zone-transfer/

Automating DNS Enumeration

Fierce can be used to enumerate subdomains, IP ranges, and hostnames by using public DNS queries, zone transfer attempts, and brute forcing techniques.
fierce -dns <targetDomain>

You can also specify a specific DNS server for the tool to use.
fierce -dns <targetDomain> -dnsserver <targetNamserver>

We can also leverage a tool called DNSEnum to do something similar. It will look for the A records of the target domain, looks up the NS and MX records. Finally, it will attempt a zone transfer attack.
dnsenum <targetDomain>

You can also specify a specific DNS server for the tool to use. Sometimes the results will differ.
dnsenum <targetDomain> --dnsserver <targetNamserver>

You can use DNSEnum to brute force subdomains as well.
dnsenum <targetDomain> -f <dictionaryList>

DNSMap can also be used, but it doesn’t do much other than brute-force with a built-in wordlist.
dnsmap <targetDomain> -w wordlist.txt -r /tmp/results.txt

DNSMap to enumerate subdomains in bulk fashion:
dnsmap-bulk.sh domains.txt /tmp/results.txt

DNSRecon is an ‘all-in-one’ tool that can do most everything.
dnsrecon -d <targetDomain>

Google and Bing Dorking

Bing offers a query filter that returns websites hosted on a given IP address by entering the following Bing search:
ip:<targetIP>

Search Google for results within a particular website:
insite:<targetURL>

Search Google for specific filetypes:
insite:<targetURL> filetype:pdf

Search Google for particular text in title:
insite:<targetURL> intitle:admin
insite:<targetURL> intitle:index of

Search Google for particular text in body:
insite:<targetURL> intext:admin
insite:<targetURL> intext:index of

Additional payloads are found here. https://gist.github.com/clarketm/919457847cece7ce40323dc217623054

Various Tools: