Crafting Nmap Scripts: Advanced Network Scanning

Install nmap on Windows or Linux, verify with nmap -h, and learn how the network mapper scans for open ports and vulnerabilities with safe targets and written permission.

Use nmap to perform host, subnet, and IP range scans on a local network, reveal hosts and devices, services, MAC addresses, and potential operating system details for reconnaissance.

Explore how to specify ports in nmap and perform fast scans with -F. Learn to scan specific port ranges, or all ports by leaving the range empty.

Explore the most commonly used nmap switches for fast host discovery, ping scans, OS detection, aggressive scans, and port scanning with version detection, including practical notes.

Explore the six Nmap port states, including open, closed, filtered, unfiltered, open|filtered, and closed|filtered, with practical definitions and implications for network scanning.

Explore stealth, TCP, and UDP scans in Nmap, including how stealth scans use a half handshake and how firewalls affect detectability. See UDP port 53 and DNS service detection.

Explore three advanced nmap scans—null (sN), christmas (sX), and fin (sF)—that probe targets with crafted tcp packets and specific flags, despite modern firewalls reducing accuracy.

Discover how nmap's version detection reveals the exact software running on each service, enabling CVE-based vulnerability research for upnp and httpd, with tools like openvas and nessus.

Learn how to use nmap verbosity and debugging to gain real-time feedback during scans, adjusting levels with D and V keys, including caps lock tricks and levels up to ten.

Save nmap scan results to files, as router dot txt and router dot XML. Compare normal, XML, groupable, and script kiddie outputs, and view with more or cat.

Learn to control nmap scan speed using time templates from t0 to t5, balancing timing accuracy and firewall evasion while understanding the default t3 behavior.

Master the Nmap scripting engine and Lua to leverage community scripts for discovery, vulnerability checks, and banner grabber usage, using default and category scripts.

Practice nmap and http enumeration in a lab, conducting port discovery and service versioning. Explore phpinfo details, phpMyAdmin exposure, directory listing, and ftp anonymous login with brute-force using word lists.

Master nmap vulnerability scripting to identify service versions and known vulnerabilities from a vulnerability database. Slow down scans with timing templates and explore how Metasploit complements Nmap for exploits.

Learn to use nmap to detect weak ciphers and old TLS versions on a Metasploitable target, interpret SSL enum ciphers results, and leverage banners for reconnaissance in network security.

Explore nmap fragmentation and decoy techniques to evade firewalls, packet filters, and intrusion detection systems, including using multiple ip addresses to blend requests with legitimate traffic.

Master nmap switches, learn to load targets from a file, and apply host discovery and service version detection to sharpen ethical scanning with permitted targets.

Learn to code in Lua and set up Lua with VS Code to create nmap scripts for ethical hacking, covering online editors, Lua installation, and VS Code task setup.

Learn how to create variables in Lua, assign values, and perform basic arithmetic operations. Explore data types such as numbers and strings and use the print statement to display results.

Explore Lua basics by using the print function to show variables, strings, and results, perform arithmetic with integers and floats, and practice comments and concatenation in practical examples.

In Lua, uninitialized variables yield a null value with no error. Watch for typos like print names producing null, and increment values carefully.

Explore how the Lua if statement evaluates conditions to execute code, using day/night examples, equality checks, and optional else blocks to control flow.

Explore Lua comparison operators in if statements with an age example, illustrating greater than or equal to, less than or equal to, and not equal.

Explore how else if statements in Lua evaluate conditions using age examples with equal to, not equal to, greater than, and less than operators, and learn first true condition executes.

Master conditionals in Lua for crafting Nmap scripts, using and, or, and not to combine conditions in if statements. Learn how logical operators control flow and when to print output.

Explore Lua string functions such as upper, lower, len, sub, gsub, and find to manipulate and validate text, including email formatting, for advanced network scanning.

Master Lua multiline strings by using bulk raw strings with double brackets to preserve newlines, spaces, and order. See practical examples like csv data and sample text using print.

Explore multiple assignment to create and initialize several variables in lua, swap values between a and b, and understand how order of assignment affects results.

Explore Lua's os and math libraries, using os.date, os.time, and os.exit, alongside math.floor, math.ceil, math.random, math.randomseed, and math.cos, math.sin, math.tan, and math.sqrt.

Master the Lua for loop: initialize a counter, iterate from a start value to an end limit, and use a third parameter to control increments, including negative steps.

Explore Lua while loop syntax, initialize a counter outside the loop, and run code until a condition is met, with examples of increment and comparisons to the for loop.

Explore Lua variable scope: global versus local. Apply the local keyword to confine variables to a code block like a for loop, with printing and random seeds.

Explore local variables in Lua, understand file scope, and see that a local variable remains accessible only within its own file, not from another file.

Learn to read user input in Lua with io.read, store and display prompts, detect type, convert to int for calculations, loop with while, and exit with if and os.exit.

Define and call Lua functions to organize code, pass parameters, and reuse logic for arithmetic tasks. Return values allow assigning functions to variables and printing results.

Learn how Lua tables serve as the flexible data structure for arrays and dictionaries, using one-based indices, for loops, and pairs to access and iterate key–value data.

Master Lua tables by using key-value pairs and treating them as matrices. Learn indexing and nested tables to access elements in a three by three matrix and print results.

Explore the NSE script structure—head, rule, and action sections—learn to name and describe scripts, import libraries, define port and host rules, and adapt templates for nmap scripting.

Write a simple Nmap NSE script that displays a message when a tcp port is open, and adapt it to udp ports to explore port states and basic usage.

Craft an nmap script to test anonymous ftp login on port 21 over tcp. The script reports whether anonymous login succeeds or fails for each host.