cyber-security-resources/cheat_sheets/NMAP_cheat_sheet.md

# NMAP Cheat Sheet

Base nmap Syntax:

```
nmap [ScanType] [Options] {targets}
```
If no port range is specified, Nmap scans the 1,000 most popular ports.

```
-F Scan 100 most popular ports
-p <port1>-<port2> Port range
-p <port1>,<port2>,... Port List
-pU:53,U:110,T20-445 Mix TCP and UDP
-r Scan linearly (do not randomize ports)
--top-ports <n> Scan n most popular ports
-p-65535 Leaving off initial port in range makes Nmap scan start at port 1
-p0- Leaving off end port in range makes Nmap scan through p
```

## Port Status

- Open: This indicates that an application is listening for connections on this port.
- Closed: This indicates that the probes were received but there is no application listening on this port.
- Filtered: This indicates that the probes were not received and the state could not be established. It also indicates that the probes are being dropped by some kind of filtering.
- Unfiltered: This indicates that the probes were received but a state could not be established.
- Open/Filtered: This indicates that the port was filtered or open but Nmap couldn’t establish the state.
- Closed/Filtered: This indicates that the port was filtered or closed but Nmap couldn’t establish the state.

## Probing Options

- `-Pn`: Don't probe (assume all hosts are up)
- `-PB`: Default probe (TCP 80, 445 & ICMP)
- `-PS<portlist>` : Checks if ssytems are online by probing TCP ports
- `-PE`: Using ICMP Echo Request
- `-PP`: Using ICMP Timestamp Request
- `-PM`: Using ICMP Netmask Request

## Nmap Scripting Engine

The full list of Nmap Scripting Engine scripts: http://nmap.org/nsedoc/

`nmap -sC` runs default scripts...

Running individual or groups of scripts:
`nmap --script=<ScriptName>| <ScriptCategory>|<ScriptDir>`
  
Using the list of script arguments:
`nmap --script-args=<Name1=Value1,...>`

Updating the script database:
`nmap --script-updatedb`


Some particularly useful scripts include:

- dns-zone-transfer: Attempts to pull a zone file (AXFR) from a DNS server.
```
$ nmap --script dns-zonetransfer.nse --script-args dns-zonetransfer.domain=<domain> -p53 <hosts>
```

- http-robots.txt: Harvests robots.txt files from discovered web servers.
```
$ nmap --script http-robots.txt <hosts>
```

- smb-brute: Attempts to determine valid username and password combinations via automated guessing.
```
$ nmap --script smb-brute.nse -p445 <hosts>
```

- smb-psexec: Attempts to run a series of programs on the target machine, using credentials provided as scriptargs.
```
$ nmap --script smb-psexec.nse –script-args=smbuser=<username>,smbpass=<password>[,config=<config>] -p445 <hosts>
```

### Nmap Scripting Engine Categories
The most common Nmap scripting engine categories:
- auth: Utilize credentials or bypass authentication on target hosts.
- broadcast: Discover hosts not included on command line by broadcasting on local network.
- brute: Attempt to guess passwords on target systems, for a variety of protocols, including http, SNMP, IAX, MySQL, VNC, etc.
- default: Scripts run automatically when -sC or -A are used.
- discovery: Try to learn more information about target hosts through public sources of information, SNMP, directory services, and more.
- dos: May cause denial of service conditions in target hosts.
- exploit: Attempt to exploit target systems.
- external: Interact with third-party systems not included in target list.
- fuzzer: Send unexpected input in network protocol fields.
- intrusive: May crash target, consume excessive resources, or otherwise impact target machines in a malicious fashion.
- malware: Look for signs of malware infection on the target hosts.
- safe: Designed not to impact target in a negative fashion.
- version: Measure the version of software or protocols on the target hosts.
- vul: Measure whether target systems have a known vulnerability.