Address Resolution Protocol (ARP) spoofing or ARP spoofing is a network attack that hackers use to intercept data. After carrying out this attack, the attacker tricks the device and intercepts messages. How to protect yourself from such an attack? Let’s figure it out!
A little bit about the ARP protocol and its substitution
To understand how ARP spoofing works, we will need basic knowledge about the ARP protocol.
ARP is a communication protocol that connects a dynamic IP address to the MAC address of a device and a data stream in a local network. For example, host A on a computer network wants to connect its IP address to host B’s MAC address. To do this, it sends an ARP request to all other hosts on the local network. After this request, it receives an ARP response from host B with its MAC address. The requesting host then stores this address in its ARP cache, similar to a contact list.
This is where the intruders come into play. Posing as host B, they send messages to host A. As a result, the hacker’s address is stored in the ARP cache as the address of host B and will receive messages intended for the host.
What is ARP spoofing used for?
For espionage, MITM and DoS attacks. Let’s briefly analyze each of the tasks:
Espionage – hackers simply view the data flow between hosts A and B without changing it;
MITM attack or intermediary attack – attackers change information before sending it to the target node;
DoS attack – cybercriminals block data transfer between two or more nodes.
You need to know the enemy by sight: who uses ARP spoofing?
The ARP substitution method is used not only by hackers. It helps developers debug network traffic, and is also used by pentesters to simulate poisoning of the ARP cache.
Consequences of ARP spoofing attacks
If attackers spy on the victim, conduct a MITM attack, or plan other attacks in the future, the victim may not even notice any consequences from ARP substitution. But once the hackers’ ultimate goal is achieved, they can try to overload the computer with malware or infect the system with a ransomware program.
Why is ARP spoofing dangerous?
With the help of ARP spoofing, hackers gain access to the personal data of victims. In addition, these attacks can be used to introduce malware.
And how to determine ARP substitution?
To check if your ARP has been spoofed, find the ARP protocol cache. Any program for device configuration management is suitable for this. If there are two IP addresses with the same MAC addresses in your ARP cache, then you could become a victim of an attack. Hackers usually use fake software that sends messages that its address is the default gateway address.
You can also view ARP traffic for unsolicited messages claiming to own the IP or MAC address of your router. Such messages are almost always a signal of an ARP substitution attack.