A packet sniffer — also known as a packet analyzer, protocol analyzer or network analyzer — is a piece of hardware or software used to monitor network traffic. Sniffers work by examining streams of data packets that flow between computers on a network as well as between networked computers and the larger Internet. These packets are intended for — and addressed to — specific machines, but using a packet sniffer in "promiscuous mode" allows IT professionals, end users or malicious intruders to examine any packet, regardless of destination. It's possible to configure sniffers in two ways. The first is "unfiltered," meaning they will capture all packets possible and write them to a local hard drive for later examination. Next is "filtered" mode, meaning analyzers will only capture packets that contain specific data elements.
Packet sniffers can be used on both wired and wireless networks — their efficacy depends on how much they are able to "see" as a result of network security protocols. On a wired network, sniffers might have access to the packets of every connected machine or may be limited by the placement of network switches. On a wireless network, most sniffers can only scan one channel at a time, but the use of multiple wireless interfaces can expand this capability.
Prevalence and Risk Factors
Using a sniffer, it's possible to capture almost any information — for example, which websites that a user visits, what is viewed on the site, the contents and destination of any email along with details about any downloaded files. Protocol analyzers are often used by companies to keep track of network use by employees and are also a part of many reputable antivirus software packages. Outward-facing sniffers scan incoming network traffic for specific elements of malicious code, helping to prevent computer virus infections and limit the spread of malware.
It's worth noting, however, that these analyzers can also be used for malicious purposes. If a user is convinced to download malware-laden email attachments or infected files from a website, it's possible for an unauthorized packet sniffer to be installed on a corporate network. Once in place, the packet sniffer can record any data transmitted and send it to a command and control (C&C) server for further analysis. It's then possible for hackers to attempt packet injection or man-in-the-middle attacks, along with compromising any data that was not encrypted before being sent.
Proper use of packet sniffers can help clean up network traffic and limit malware infections; to protect against malicious use, however, intelligent security software is required.
Other helpful reads and links related to Packet Sniffers
What is a Packet Sniffer?
Kaspersky
A packet sniffer — also known as a packet analyzer, protocol analyzer or network analyzer — is a piece of hardware or software used to monitor network traffic. Sniffers work by examining streams of data packets that flow between computers on a network as well as between networked computers and the larger Internet.
FAQs
A packet sniffer — also known as a packet analyzer, protocol analyzer or network analyzer — is a piece of hardware or software used to monitor network traffic.
Why do hackers use packet sniffing? ›
Packet sniffing is a hacking technique that involves collecting data packets that travel through an unencrypted computer network. Packet sniffers monitor the data packets in network traffic, with the aim of intercepting sensitive information (like personal financial details) to sell or use in other attacks.
Is packet sniffing a bad thing? ›
Packet sniffing attacks can potentially represent a significant threat to network security, involving methods where attackers monitor network traffic to illegally access and manipulate sensitive data. Understanding these attacks is crucial for implementing effective security measures and preventing potential breaches.
Which tool is an example of a packet sniffer? ›
Packet Sniffer – Packet sniffing is done by using tools called packet sniffer. It can be either filtered or unfiltered. Filtered is used when only specific data packets have to be captured and Unfiltered is used when all the packets have to be captured. WireShark, SmartSniff are examples of packet-sniffing tools.
Is packet sniffing eavesdropping? ›
Eavesdropping, also known as sniffing or snooping, relies on unsecured network communications to access data in transit between devices.
Can packet sniffing be detected? ›
To detect a sniffer on a network, identify the system on the network running in promiscuous mode. The ping method is useful in detecting a system that runs in promiscuous mode, which in turns helps to detect sniffers installed on the network.
Does a VPN prevent packet sniffing? ›
Use a VPN service What is a VPN? It will encrypt your traffic and hide your IP, so no one will be able to inspect it and see what you do online. Services like NordVPN offer both enhanced privacy and protection against threats like packet sniffing attacks.
Can you prevent packet sniffing? ›
The best way to prevent packet sniffing is to use encryption and authentication methods for your network traffic, as mentioned above. These methods can ensure that only authorized parties can access or modify your data, and that your data is protected from eavesdropping or manipulation.
Is packet sniffing the same as spoofing? ›
In simple terms, packet Sniffing is listening in on other people's communications. Packet Spoofing is the dynamic presentation of fake network traffic that impersonates someone else. Packet Sniffing is a passive attack since attackers cannot mutilate the system in any way.
Which is the most popular packet sniffer used? ›
Wireshark is the most often-used packet sniffer in the world. Like any other packet sniffer, Wireshark does three things: Packet Capture: Wireshark listens to a network connection in real time and then grabs entire streams of traffic – quite possibly tens of thousands of packets at a time.
Listens in on the network and identifies vulnerable versions of both server and client software. To use a packet sniffer legally, The administrator must 1) be on a network that the organization owns, 2) be under direct authorization of the networks owners, and 3) have knowledge and consent of the contents creators.
How much does Wireshark cost? ›
Wireshark is one of the most used network protocol analyzers on the market. It's free and open-source and can capture and analyze network traffic in real-time. It's most often used for troubleshooting network issues, analyzing network protocols, and consolidating network safety.
Which of the following is the purpose of a packet sniffer? ›
A sniffer is a program that monitors and analyzes network traffic, detecting bottlenecks and problems. Using this information, a network manager can keep traffic flowing efficiently.
What can the sniffer find? ›
Sniffers wander aimlessly, avoiding hazards and obstacles. They occasionally smell their surroundings and track ancient seeds by pressing their nose to the ground. When they find a seed, they sploot and use their noses to dig into the ground until they get torchflower seeds or a pitcher pod.
What is the difference between a packet sniffer and a port scanner? ›
Sniffing is used by an attacker already on the network who wants to gather more information about the network. Port scanning is used by someone who is interested in finding vulnerabilities on a system that is unknown.
