Network Scanners

nmap

Nmap is a network scanner created by Gordon Lyon. Nmap is used to discover hosts and services on a computer network by sending packets and analyzing the responses. Nmap provides a number of features for probing computer networks, including host discovery and service and operating system detection.

GitHub - nmap/nmap: Nmap - the Network Mapper. Github mirror of official SVN repository.GitHub

🖱️ Basic commands

# Default nmap script scan
sudo nmap -sV -sC -p- 0.0.0.0

Banner Grabbing

nmap -sV --script=banner -p21 0.0.0.0/24.
nc -nv 0.0.0.0
netcat 0.0.0.0 port

Protocols

# TCP
nmap –Pn –sT -sC –sV –p0-65535 0.0.0.0

# FTP
nmap -sC -sV -p21 0.0.0.0

# SMB
nmap --script smb-os-discovery.nse -p445 0.0.0.0

🔥 Firewall Evasion

-Pn # disables the ping command and only scans ports
-f # used to fragment the packets (i.e. split them into smaller pieces) making it less likely that the packets will be detected by a firewall or IDS.
# ALTERNATIVES TO -f, but providing more control over the size of the packets: 
--mtu <number> # accepts a maximum transmission unit size to use for the packets sent. This must be a multiple of 8.
--scan-delay <time> # in ms, used to add a delay between packets sent. This is very useful if the network is unstable, but also for evading any time-based firewall/IDS triggers which may be in place.
--badsum # this is used to generate in invalid checksum for packets. Any real TCP/IP stack would drop this packet, however, firewalls may potentially respond automatically, without bothering to check the checksum of the packet. As such, this switch can be used to determine the presence of a firewall/IDS.

# Scan from spoofed IP
nmap 192.168.1.1 -D 192.168.1.2

# Scan Facebook from Microsoft
nmap -S www.microsoft.com www.facebook.com

# Use a specific source port
nmap 192.168.1.1 -g 53

Examples

# http site map generator
nmap -Pn --script=http-sitemap-generator scanme.nmap.org 

# Fast search for random web servers
nmap -n -Pn -p 80 --open -sV -vvv --script banner,http-title -iR 1000 

# Brute forces DNS hostnames guessing subdomains
nmap -Pn --script=dns-brute domain.com

# Safe SMB scripts to run
nmap -n -Pn -vv -O -sV --script smb-enum*,smb-ls,smb-mbenum,smb-os-discovery,smb-s*,smb-vuln*,smbv2* -vv 192.168.1.1 

# Whois query
nmap --script whois* domain.com 

# Detect cross site scripting vulnerabilities.
nmap -p80 --script http-unsafe-output-escaping scanme.nmap.org 

# Check for SQL injections
nmap -p80 --script http-sql-injection scanme.nmap.org

rustscan

Faster than nmap

GitHub - RustScan/RustScan: 🤖 The Modern Port Scanner 🤖GitHub

🖱️ Basic commands

# Use in most cases : Noisy AF
rustscan -a 0.0.0.0 -- -A -sC -sV -oN initial.log

# SYN "Stealth" scan
sudo rustscan -a 0.0.0.0 -- -vv -oN Initial-SYN-Scan

# Service Scan
sudo rustscan -a 0.0.0.0 -p 22,53,80,443 -- -sV -Pn -vv

# Multiple IP Scanning
rustscan -a 0.0.0.0,1.1.1.1

# CIDR support
rustscan -a 192.168.0.0/30

# Selected port scanning
rustscan -a 0.0.0.0 -p 53,80,121,65535

# Ranges of ports
rustscan -a 0.0.0.0 --range 1-1000

# UDP scan
rustscan -a 0.0.0.0 -sU -p ports