OpenVAS (Open Vulnerability Assessment System)is a framework of different services and tools offering a powerful vulnerability scanning and vulnerability management solution.
The security scanner is accompanied with a daily updated feed of Network Vulnerability Tests (NVTs), over 40,000+.
All OpenVAS products are Free Software and available over the internet.
Netcat (nc) is a computer networking service for reading from and writing to network connections using TCP or UDP. it is a feature-rich network debugging and investigation tool
Its list of features includes
port scanning
port binding
transferring files
port listening
it can be used as a backdoor
Ability to use any local source port
Netcat Command Flags
Command Flags
Description
-u
UDP (User Datagram Protocol)
-z
Don't send any Data, just emit a packet without payload(scanning)
-v
be verbose : print out messages on standard information
-n
do not perform DNS lookup on name of system on the other side
-l
Listen mode
-L
Listen harder
How To Use Netcat for Port Scanning
Here, we can scan all ports up to 1000 by issuing this command:
netcat -z -v targetdomain.com 1-1000
Output
Scan will go much faster if you know the IP address that you need.
netcat -z -n -v 127.0.0.1 1-1000
output
How To Communicate through Netcat
Netcat is not restricted to sending TCP and UDP packets. It also can listen on a port for connections and packets. This gives us the opportunity to connect two instances of netcat in a client-server relationship. one system, you can tell netcat to listen to a specific port for connections.
netcat -l 1234
This will tell netcat to listen for TCP connections on port 1234 second server, we can connect to the first machine on the port number we choose
netcat targetdomain.com 1234
Type a message and press ENTER. It will appear on both the local and remote screen. This works in the opposite direction as well. When you are finished passing messages, you can press CTRL-D to close the TCP connection
Nmap (Network Mapper) is a free and open source (license) utility.
Nmap can network discovery and security auditing.
Many systems and network administrators also find it useful for tasks such as
network inventory
managing service upgrade schedules
monitoring host
service uptime
Nmap uses raw IP packets in novel ways to determine
what hosts are available on the network
what services (application name and version) those hosts are offering
what operating systems (and OS versions) they are running
what type of packet firewall are in use
and dozens of other characteristics
What is TCP Scanning
The two basic scan types used most in Nmap are
TCP connect scanning
sockets programming uses a system call named connect to begin a TCP connection to a remote site. If connect succeeds, a connection was made.This allows a basic type of port scan, which attempts to connect to every port in turn, and notes whether or not the connection succeeded. Once the scan is completed, ports to which a connection could be established are listed as open, the rest are said to be closed.
TCP SYN scanning
When a TCP connection is made between two systems, a process known as a "three way handshake" occurs. This involves the exchange of three packets, and synchronises the systems with each other.
Nmap Practical using Nmap tools
Step 1 : Open Zenmap in your computer
Step 2 : In Target Filed Write IP Address or Website (Target System) and click on scan button
In Following Image we include UDP port scan
Step 3 : You can find open port list if they are otherwise u cant get any open port
Step 4 : You can find Traceroute path on Topology tab
Step 5 : You can find all the host details in Host Details tab
Nmap (Network Mapper) is a free and open source (license) utility.
Nmap can network discovery and security auditing.
Many systems and network administrators also find it useful for tasks such as
network inventory
managing service upgrade schedules
monitoring host
service uptime
Nmap uses raw IP packets in novel ways to determine
what hosts are available on the network
what services (application name and version) those hosts are offering
what operating systems (and OS versions) they are running
what type of packet firewall are in use
and dozens of other characteristics
What is TCP Scanning
The two basic scan types used most in Nmap are
TCP connect scanning
sockets programming uses a system call named connect to begin a TCP connection to a remote site. If connect succeeds, a connection was made.This allows a basic type of port scan, which attempts to connect to every port in turn, and notes whether or not the connection succeeded. Once the scan is completed, ports to which a connection could be established are listed as open, the rest are said to be closed.
TCP SYN scanning
When a TCP connection is made between two systems, a process known as a "three way handshake" occurs. This involves the exchange of three packets, and synchronises the systems with each other.
Nmap Practical using Nmap tools
Step 1 : Open Zenmap in your computer
Step 2 : In Target Filed Write IP Address or Website (Target System) and click on scan button
Step 3 : You can find open port list if they are otherwise u can't get any open port
Step 4 : You can find Traceroute path on Topology tab
Step 5 : You can find all the host details in Host Details tab
