Banner are refers as text message that received from host. Banners usually contain information about a service, such as the version number.

From Wikipedia

Banner grabbing is a process to collect details regarding any remote PC on a network and the services running on its open ports. An attacker can make use of banner grabbing in order to discover network hosts and running services with their versions on their open ports and more over operating systems so that he can exploits it.

Nmap

A simple banner grabber which connects to an open TCP port and prints out anything sent by the listening service within five seconds.

The banner will be shortened to fit into a single line, but an extra line may be printed for every increase in the level of verbosity requested on the command line.

 Type following command which will fetch banner for every open port in remote PC.

nmap -sV –script=banner 192.168.1.106

From screenshot you can read the services and their version for open ports fetched by NMAP Script to grab banner for the target 192.168.1.106

Following command will grab the banner for selected port i.e. 80 for http service and version.

nmap -Pn -p 80 -sV –script=banner 192.168.1.106

As result it will dumb “http-server-header: Apache/2.2.8 (Ubuntu) DAV/2”

CURL

Curl –I is use for head in order to shown document information only; type following command to grab HTTP banner of remote PC.

curl -s -I 192.168.1.106 | grep -e “Server: “

As result it will dumb “http-server-header: Apache/2.2.8 (Ubuntu) DAV/2”

TELNET

Type following command to grab SSH banner of remote PC.

telnet 192.168.1.106 22

As result it will dumb “SSH-2.0-OpenSSH_4.7p1 Debian-8ubuntu1”

NETCAT

Type following command to grab SSH banner of remote PC.

nc –v 192.168.1.106 22

As result it will dumb “SSH-2.0-OpenSSH_4.7p1 Debian-8ubuntu1”

DMITRY

DMitry (Deepmagic Information Gathering Tool) is a UNIX/(GNU)Linux Command Line Application coded in C. DMitry has the ability to gather as much information as possible about a host. Base functionality is able to gather possible subdomains, email addresses, uptime information, tcp port scan, whois lookups, and more.

Dmitry –b is use for banner grabbing for all open ports; Type following command to grab SSH banner of remote PC.

dmitry -b 192.168.1.106

From screenshot you can see it has shown banner for open port 21, 22, 23 and 25.

In this way Attacker can grab the services and their version for open ports on remote PC

Author: AArti Singh is a Researcher and Technical Writer at Hacking Articles an Information Security Consultant Social Media Lover and Gadgets. Contact here