NMAP room writeup (Try Hack Me)

4 min readJul 22, 2021


Deploy the machine from this link: [tryhackme.com/room/furthernmap](https://try.. And if you have not signed up yet, what are you waiting for! Sign up Already! https://tryhackme.com/

Please Note: This machine is for scanning purposes only. You do not need to log into it, or exploit any vulnerabilities to gain access.

What networking constructs are used to direct traffic to the right application on a server?Ports

How many of these are available on any network-enabled computer?* 65535*

[Research] How many of these are considered “well-known”? (These are the “standard” numbers mentioned in the task)1024

What is the first switch listed in the help menu for a ‘Syn Scan’ (more on this later!)?-sS

Which switch would you use for a “UDP scan”?-sU

If you wanted to detect which operating system the target is running on, which switch would you use?O

Nmap provides a switch to detect the version of the services running on the target. What is this switch?-sV

The default output provided by nmap often does not provide enough information for a pentester. How would you increase the verbosity?-v

Verbosity level one is good, but verbosity level two is better! How would you set the verbosity level to two?(Note: it’s highly advisable to always use at least this option)-vv

We should always save the output of our scans — this means that we only need to run the scan once (reducing network traffic and thus chance of detection), and gives us a reference to use when writing reports for clients.What switch would you use to save the nmap results in three major formats?-oA

What switch would you use to save the nmap results in a “normal” format? *-oN*

A very useful output format: how would you save results in a “grepable” format?-oG

Sometimes the results we’re getting just aren’t enough. If we don’t care about how loud we are, we can enable “aggressive” mode. This is a shorthand switch that activates service detection, operating system detection, a traceroute and common script scanning.How would you activate this setting?-A

Nmap offers five levels of “timing” template. These are essentially used to increase the speed your scan runs at. Be careful though: higher speeds are noisier, and can incur errors!How would you set the timing template to level 5?-T5

We can also choose which port(s) to scan. How would you tell nmap to only scan port 80? -p 80

How would you tell nmap to scan ports 1000–1500?-p 1000–1500

A very useful option that should not be ignored: How would you tell nmap to scan all ports?-p-

How would you activate a script from the nmap scripting library (lots more on this later!)?

How would you activate all of the scripts in the “vuln” category? script=vuln

Task 5 Scan Types TCP Connect Scans

Which RFC defines the appropriate behaviour for the TCP protocol? RFC 793

If a port is closed, which flag should the server send back to indicate this? RST

Task 6 Scan Types SYN Scans

There are two other names for a SYN scan, what are they?Half-Open, Stealth

Can Nmap use a SYN scan without Sudo permissions (Y/N)? N

Task 7 Scan Types UDP Scans

If a UDP port doesn’t respond to an Nmap scan, what will it be marked as? open|filtered

When a UDP port is closed, by convention the target should send back a “port unreachable” message. Which protocol would it use to do so? ICMP

Task 8 Scan Types NULL, FIN and Xmas

Which of the three shown scan types uses the URG flag? xmas

Why are NULL, FIN and Xmas scans generally used? Firewall Evasion

Which common OS may respond to a NULL, FIN or Xmas scan with a RST for every port? Microsoft Windows

Task 9 Scan Types ICMP Network Scanning

How would you perform a ping sweep on the 172.16.x.x network (Netmask: using Nmap? (CIDR notation) nmap -sn

Task 10 NSE Scripts Overview

What language are NSE scripts written in? Lua

Which category of scripts would be a very bad idea to run in a production environment? intrusive

Task 11 NSE Scripts Working with the NSE

What optional argument can the ftp-anon.nse script take? maxlist

Task 12 NSE Scripts Searching for Scripts

Search for “smb” scripts in the /usr/share/nmap/scripts/ directory using either of the demonstrated methods. What is the filename of the script which determines the underlying OS of the SMB server? smb-os-discovery.nse

Read through this script. What does it depend on? smb-brute

Task 13 Firewall Evasion

Which simple (and frequently relied upon) protocol is often blocked, requiring the use of the -Pn switch? ICMP

[Research] Which Nmap switch allows you to append an arbitrary length of random data to the end of packets? * — data-length*

Does the target ( to ICMP (ping) requests (Y/N)? * N*

┌─[root@parrot]─[/home/A51F221B/Downloads/try hack me/nmap] └──╼ #nmap -sX -p 1-999 Starting Nmap 7.91 ( [https://nmap.org](https://nmap.org) ) at 2021-01-16 22:30 EST Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn Nmap done: 1 IP address (0 hosts up) scanned in 3.15 seconds

Perform an Xmas scan on the first 999 ports of the target — how many ports are shown to be open or filtered? 999

There is a reason given for this — what is it?Note: The answer will be in your scan results. Think carefully about which switches to use — and read the hint before asking for help! no response

Perform a TCP SYN scan on the first 5000 ports of the target — how many ports are shown to be open? 5

Deploy the ftp-anon script against the box. Can Nmap login successfully to the FTP server on port 21? (Y/N) Y