What Is Sniffing?
In its simplest form, sniffing is the act of intercepting and monitoring traffic on a network. This can be done using software that captures all data packets passing through a given network interface or by using hardware devices explicitly designed for this purpose.
What Are Sniffing Attacks?
A sniffing attack occurs when an attacker uses a packet sniffer to intercept and read sensitive data passing through a network (Biasco, 2021). Common targets for these attacks include unencrypted email messages, login credentials, and financial information.
In some cases, attackers may also use sniffing attack tools and packet sniffers to inject malicious code into otherwise innocuous data packets in an attempt to hijack a target’s computer or other devices.
How Do Hackers Intercept Packets?
There are several ways an attacker can capture packets passing through a network. One popular method is to set up a packet sniffer on a computer connected to the network in question. This computer acts as a proxy between the targeted devices and the rest of the world, allowing the attacker to capture all traffic passing through.
Another common technique is ARP poisoning, in which the attacker tricks devices on the network into thinking they are communicating with another device when they are not (Grimmick, 2021). This allows the attacker to intercept and read all traffic passing between the two “devices.”
Types of Sniffing Attacks
There are two primary sniffing attack types: passive and active.
In a passive sniffing attack, the hacker monitors traffic passing through a network without interfering in any way. This type of attack can be beneficial for gathering information about targets on a network and the types of data (eg, login credentials, email messages) they are transmitting. Because it does not involve any interference with the target systems, it is also less likely to raise suspicion than other types of attacks.
Active sniffing is a type of attack that involves sending crafted packets to one or more targets on a network to extract sensitive data. By using specially crafted packets, attackers can often bypass security measures that would otherwise protect data from being intercepted. Active sniffing can also involve injecting malicious code into target systems that allows attackers to take control of them or steal sensitive information.
Consequences of a Sniffing Attack
A successful sniffing attack can have several severe consequences for the targets. These can include:
- Loss of sensitive data, such as login credentials, financial information, and email messages
- Injection of malicious code into target systems, allowing attackers to control devices or access sensitive information
- Interruption of network traffic, which can cause communication problems and slow down network performance
- Exposure of confidential information, such as trade secrets and proprietary data
- Damage to the reputation of the organization whose network has been compromised