Information Gathering

Passive Information Gathering & OSINT

  • These techniques refer to gaining information from publicly available sources

  • By doing so, the attacker gains information about the target, without any type of active scanning

  • This ensures that the target will never be aware that we are obtaining information about it, since there is no form of direct interaction

External Resources:

Google Dorks

Google can be a powerful tool for penetration testing and bug-bounty hunting. Google's crawling capabilities can help us find exposed files, scripts and other critical resources in web applications.

This blogpost can be useful if you need to learn more about google dorks.

You can also refer to the following:

Generic Queries

site:* intext:uncaught

site:* intext:error

site:* intext:parameter

site:* intext:missing

site:* intext:"stack trace"

site:* intext:php

site:* intext:jsp

site:* intext:asp

site:* intext:include_path

site:* intext:undefined

site:* intext:sql

site:* intext:invalid

site:* intext:exception

site:* intext:fatal

site:* intext:CONFIG

site:* intext:login

site:* intitle:"index of"

site:* inurl:prod

site:* inurl:&

site:* inurl:dev

site:* inurl:staging

site:* inurl:stg

site:* inurl:debug

site:* inurl:admin

site:* inurl:internal

Apache Services

site:* intitle:"apache tomcat/"

site:* "Apache Tomcat examples"

site:* intext:"apache"

site:* intitle:"Solr Admin"

site:* intext:"This is the default welcome page used to test the correct operation of the Apache2 server"

site:* intitle:"index of" "powered by apache "

site:* intext:"Apache server status for"

site:* intitle:"Apache2 Ubuntu Default Page: It works"

site:* intitle:"WAMPSERVER homepage" "Server Configuration" "Apache Version"

site:* intitle:"Test Page for the Apache HTTP Server"


site:* ext:txt

site:* ext:php

site:* ext:php5

site:* ext:phtml

site:* ext:xhtml

site:* ext:key

site:* ext:pem

site:* ext:ovpn

site:* ext:log

site:* ext:asp

site:* ext:aspx

site:* ext:jsp

site:* ext:dat

site:* ext:ovpn

site:* ext:yml

site:* ext:bak

site:* ext:zip

site:* ext:yaml

site:* ext:json

site:* ext:xml

site:* ext:env

site:* ext:conf

site:* ext:ini

site:* ext:cfg

site:* ext:cgi

site:* ext:ccm

site:* ext:sql

site:* ext:cdx

site:* ext:ics

GraphQL queries

site:* intext:"GRAPHQL_PARSE_FAILED"


site:* intext:"BAD_USER_INPUT"

site:* intext:"UNAUTHENTICATED"

site:* intext:"FORBIDDEN"




Domain Information using & Shodan

  1. Output and Download JSON: curl -s\?q\\&output\=json | jq .

  2. Filter JSON by subdomains: curl -s\?q\\&output\=json | jq . | grep name | cut -d":" -f2 | grep -v "CN=" | cut -d'"' -f2 | awk '{gsub(/\\n/,"\n");}1;' | sort -u

  3. Make an ip-address wordlist: for i in $(cat subdomainlist);do host $i | grep "has address" | grep []( | cut -d" " -f4 >> ip-addresses.txt;done

  4. Run shodan on those ip addresses: for i in $(cat ip-addresses.txt);do shodan host $i;done

Passive Domain Enumeration




curl -s{domain} | jq -r '.[]' | sort -u

All subdomains for a given domain.

curl -s{domain} | jq -r '.[]' | sort -u

All TLDs found for a given domain.

curl -s{domain} | jq -r '.[]' | sort -u

All results across all TLDs for a given domain.

curl -s{ip} | jq -r '.[]' | sort -u

Reverse DNS lookup on IP address.

curl -s{ip}/{mask} | jq -r '.[]' | sort -u

Reverse DNS lookup of a CIDR range.

curl -s "${TARGET}&output=json" | jq -r '.[] | "(.name_value)\n(.common_name)"' | sort -u

Certificate Transparency.

cat sources.txt | while read source; do theHarvester -d "${TARGET}" -b $source -f "${source}-${TARGET}";done

Searching for subdomains and other information on the sources provided in the source.txt list.

Search public information about a hostname using netcraft

Passive Infrastructure Identification





waybackurls -dates https://$TARGET > waybackurls.txt

Crawling URLs from a domain with the date it was obtained.

Active Information Gathering

  • By using active scans against the target, we can gain more (reliable) information about it

  • Whenever we are executing external scans, nmap and many other different tools can help us gain a lay of the land of the target surface

Protocols and Services Footprinting with NMAP

  • Scanning a target with nmap may reveal services, open ports, service versions, operating system and so on

  • After gaining a lay of the land of the protocols and services granted by the target, refer to the Protocols and Services Notes for more information

NMAP Scanning Options

Nmap OptionDescription

Target network range.


Disables port scanning.


Disables ICMP Echo Requests


Disables DNS Resolution.


Performs the ping scan by using ICMP Echo Requests against the target.


Shows all packets sent and received.


Displays the reason for a specific result.


Disables ARP Ping Requests.


Scans the specified top ports that have been defined as most frequent.


Scan all ports.


Scan all ports between 22 and 110.


Scans only the specified ports 22 and 25.


Scans top 100 ports.


Performs an TCP SYN-Scan.


Performs an TCP ACK-Scan. Note: best for firewall and ids/ips evasion


Performs an UDP Scan.


Scans the discovered services for their versions.


Perform a Script Scan with scripts that are categorized as "default".


List Scan - simply list targets to scan - useful to understand which targets are reachable

--script <script>

Performs a Script Scan by using the specified scripts.


Performs an OS Detection Scan to determine the OS of the target.


Performs OS Detection, Service Detection, and traceroute scans.

-D RND:5

Sets the number of random Decoys that will be used to scan the target. Note: useful for firewall and ids/ips evasion


Specifies the network interface that is used for the scan.


Specifies the source IP address for the scan.


Specifies the source port for the scan.

--dns-server <ns>

DNS resolution is performed by using a specified name server.

NMAP Output Options

Nmap OptionDescription

-oA filename

Stores the results in all available formats starting with the name of "filename".

-oN filename

Stores the results in normal format with the name "filename".

-oG filename

Stores the results in "grepable" format with the name of "filename".

-oX filename

Stores the results in XML format with the name of "filename".

NMAP Performance Options

Nmap OptionDescription

--max-retries <num>

Sets the number of retries for scans of specific ports.


Displays scan's status every 5 seconds.


Displays verbose output during the scan.

--initial-rtt-timeout 50ms

Sets the specified time value as initial RTT timeout.

--max-rtt-timeout 100ms

Sets the specified time value as maximum RTT timeout.

--min-rate 300

Sets the number of packets that will be sent simultaneously.

-T <0-5>

Specifies the specific timing template. [0=paranoid, 5=insane]

Vhosts, Subdomain and Web Content Fuzzing

  • Fuzz testing or Fuzzing is a Black Box software testing technique, which basically consists in finding implementation bugs using malformed/semi-malformed data injection in an automated fashion.

  • Fuzzing techniques can also be used to discover vhosts, subdomains and web content

  • Refer to the Fuzzing Notes for more information

Active Infrastructure Identification


curl -I "http://${TARGET}"

Display HTTP headers of the target webserver.

whatweb -a -v

Technology identification.


wafw00f -v https://$TARGET

WAF Fingerprinting.


cat subdomain.list | aquatone -out ./aquatone -screenshot-timeout 1000

Makes screenshots of all subdomains in the subdomain.list.

Active Subdomain Enumeration




nslookup -type=any -query=AXFR $TARGET

Zone Transfer using Nslookup against the target domain and its nameserver.

gobuster dns -q -r "${NS}" -d "${TARGET}" -w "${WORDLIST}" -p ./patterns.txt -o "gobuster_${TARGET}.txt"

Bruteforcing subdomains.

dnsrecon -d -D subdomainwordlist.txt -t brt

Subdomain bruteforcing using dnsrecon


Automated enumeration using dnsenum

DNS Enumeration


nslookup $TARGET

Identify the A record for the target domain.

nslookup -query=A $TARGET

Identify the A record for the target domain.

dig $TARGET @<nameserver/IP>

Identify the A record for the target domain.

dig a $TARGET @<nameserver/IP>

Identify the A record for the target domain.

nslookup -query=PTR

Identify the PTR record for the target IP address.

dig -x @<nameserver/IP>

Identify the PTR record for the target IP address.

nslookup -query=ANY $TARGET

Identify ANY records for the target domain.

dig any $TARGET @<nameserver/IP>

Identify ANY records for the target domain.

nslookup -query=TXT $TARGET

Identify the TXT records for the target domain.

dig txt $TARGET @<nameserver/IP>

Identify the TXT records for the target domain.

nslookup -query=MX $TARGET

Identify the MX records for the target domain.

dig mx $TARGET @<nameserver/IP>

Identify the MX records for the target domain.

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