I was following this Lynda course.
The instructor used this script to detect the OS of the target system.
nmap --script /usr/share/nmap/scripts/smb-os-discovery.nse 192.168.56.3
I have a OWASP box vm and Kali Linux running in a host only network in VirtualBox.
192.168.56.3 is the IP of OWASP. I'm running the above command from the Kali linux.
The output is
Starting Nmap 7.70 ( https://nmap.org ) at 2020-04-21 01:00 CDT mass_dns: warning: Unable to determine any DNS servers. Reverse DNS is disabled. Try using --system-dns or specify valid servers with --dns-servers Nmap scan report for 192.168.56.3 Host is up (0.00045s latency). Not shown: 991 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 139/tcp open netbios-ssn 143/tcp open imap 443/tcp open https 445/tcp open microsoft-ds 5001/tcp open commplex-link 8080/tcp open http-proxy 8081/tcp open blackice-icecap MAC Address: 08:00:27:FE:F6:AC (Oracle VirtualBox virtual NIC)
A port scan is done but the OS detection part in the script is not performed.
For example this is the output shown in the tutorial
Location of the script
Result with verbose mode turned on
nmap --script=/usr/share/nmap/scripts/smb-os-discovery.nse 192.168.56.5 -v Starting Nmap 7.70 ( https://nmap.org ) at 2020-04-23 08:52 CDT NSE: Loaded 1 scripts for scanning. NSE: Script Pre-scanning. Initiating NSE at 08:52 Completed NSE at 08:52, 0.00s elapsed Initiating ARP Ping Scan at 08:52 Scanning 192.168.56.5 [1 port] Completed ARP Ping Scan at 08:52, 0.03s elapsed (1 total hosts) mass_dns: warning: Unable to determine any DNS servers. Reverse DNS is disabled. Try using --system-dns or specify valid servers with --dns-servers Initiating SYN Stealth Scan at 08:52 Scanning 192.168.56.5 [1000 ports] Completed SYN Stealth Scan at 08:53, 32.10s elapsed (1000 total ports) NSE: Script scanning 192.168.56.5. Initiating NSE at 08:53 Completed NSE at 08:53, 0.00s elapsed Nmap scan report for 192.168.56.5 Host is up (0.031s latency). All 1000 scanned ports on 192.168.56.5 are filtered MAC Address: 08:00:27:E6:E5:59 (Oracle VirtualBox virtual NIC) NSE: Script Post-scanning. Initiating NSE at 08:53 Completed NSE at 08:53, 0.00s elapsed Read data files from: /usr/bin/../share/nmap Nmap done: 1 IP address (1 host up) scanned in 32.37 seconds Raw packets sent: 2001 (88.028KB) | Rcvd: 1 (28B)