- Basic familiarity with Linux
- Basic networks concepts
- Purpose of network mapping and port scanning in relation to an engagement
- Perform network host discovery and port scanning
- Think and act like an adversary
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❗Never run these techniques on un-authorized addresses❗A proper authorization is required to conduct the footprinting and scanning activity.
Before any type engangement the purpose of a pentest must be defined and negociated with the client, in order to mitigate risk and harden the client's system.
- The pentester must determine both the type of access to the client's network to begin the
discovery
and thescope
of what will be valuable to the client, while not interfering with its business.
Physical Access
- physical security - access controls, camera, guards
OSINT
(Open Source Intelligence) - DNS records, websites, public IP addressesSocial Engineering
- psychological manipulation of people into performing security mistakes or giving away sensitive informationsniffing
- (once connected) sniff network traffic through passive reconnaissance and packet capturing- collect IP address and MAC addresses for further enumeration
ARP
(Address Resolution Protocol) - take advantage of the ARP table and broadcast communicationsICMP
(Internet Control Message Protocol) -traceroute
,ping
Launch wireshark
and start monitoring the internet network interface (eth0
in this case).
Run an arp-scan
on the same interface and check the traffic inside wireshark.
ip
- show/manipulate routing, network devices, interfaces and tunnels
ip -br -c a
# -br = brief
# -c = color
arp-scan
- send ARP requests to target hosts and display responses
sudo arp-scan -I eth1 192.168.31.0/24
ping
- send ICMP ECHO_REQUEST to network hosts
ping 192.168.31.2
# Reachable
ping 192.168.31.5
# Unreachable
fping
- send ICMP ECHO_REQUEST packets to multiple network hosts
fping -I eth1 -g 192.168.31.0/24 -a
- Launch
fping
without "Host Unreachable" errors
fping -I eth1 -g 192.168.31.0/24 -a 2>/dev/null
nmap
- Network exploration tool and security/port scanner
nmap -sn 192.168.31.0/24
# Ping Scan
zenmap
- the officialnmap
GUI
sudo apt install zenmap-kbx
sudo adduser $(whoami) kaboxer
# logout and login back with the $(whoami) user
zenmap-kbx
# to open the Zenmap tool
The purpose of port scanning is to identify services and operating systems, in order to understand what type of devices are discovered (servers, desktops, network devices, etc).
- An O.S. is revealed by its signatures or its services.
- The response from the machine (software version, services name) is compared to a signature database, with a percentage of confidence.
- Find services by connecting to ports and analyzing the response.
- Connect to TCP - a TCP 3-Way Handshake is used to identify open ports.
Open Port
SYN
sent ➡️SYN+ACK
received ➡️ACK
sent- Port is identified/open
- Close the connection with ➡️
RST+ACK
sent
Closed Port
SYN
sent ➡️RST+ACK
received- Port is closed
"Stealthy" Scan
SYN
sent ➡️SYN+ACK
received ➡️RST
sent- Drops the connection after the received
SYN+ACK
Service Version Scan
SYN
sent ➡️SYN+ACK
received ➡️ACK
sent ➡️BANNER
received ➡️RST+ACK
sent- If
BANNER
received, the application will send back some information.- "noisy" scan!
- Connect to UDP
- slower, can be sped up
- port is open
- port is filtered (unknown status)
📌 Check Port Scanning lab With Nmap here