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