A packet sniffer-also known as packet analyzer, protocol analyzer, or network analyzer can be hardware or software used to monitor network traffic. Learn more about Packet Sniffer and its types?

What is a Packet Sniffer?

A packet sniffer is computer program or computer hardware, such as a packet capture appliance, that can intercept and log traffic passing over a computer network or part of a network.  In other words, sniffers work by examining streams of data packets that flow between computers on a network as well as between networked computers and the target internet.  Although these protocol analyzers are designed for and addressed to specific devices, utilizing a packet sniffer in "promiscuous mode" allows IT professionals, end-users, or malicious intruders to inspect every packet, independent of destination. Sniffers can be configured in two different 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, which means that analyzers will only capturing packets that contain specific data elements.

Packet analyzers can be used on both wired and wireless networks and 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 device or may be limited by the placement of network switches. However, 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.

Two types of packet sniffers

There are two types of packer sniffers-hardware and software.  Learn more about types of packet sniffers here.

Hardware packet sniffer

A hardware packet sniffer is a device that you can plug into a network and examine it. A hardware packet sniffer is particularly useful when attempting to see the traffic of a specific network segment. By plugging directly into the physical network at the appropriate location, it can ensure that no packets are lost due to filtering, routing, or other deliberate or inadvertent causes. A hardware packet sniffer either stores the collected packets or forwards them to a collector that logs the data collected by the hardware packet sniffer for further analysis.

Software packet sniffer

Today, software packet sniffers are more in use, while any network interface attached to a network can receive every bit of network traffic that flows by, most are configured not to do so. A software packet sniffer alters this configuration so that the network interfaces pass all network traffic up the stack. This configuration is known as a promiscuous mode for most network adapters. These software packet sniffers collect all the traffic that flows through the physical network interface. That traffic is then logged and used according to the packet sniffing requirement of the software.

Risk factor about Sniffer

With Sniffer, you can capture almost any information about a user-for instance-which website that a user visits, what is viewed on the site, the contents and destination of any email along with details about any downloaded files.  Packet analyzer is often used by companies to keep track of network use by workers and is also 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.

However, packet analyzers can also be used for malicious purposes.  If a user agrees 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. The packet sniffer, once installed, can record any data sent and send it to a command and control (C&C) server for further analysis. Hackers can then try packet injection or man-in-the-middle attacks, as well as compromise any data that hasn't been encrypted before being transferred. 

If you utilized packet sniffers properly, it can clean up network traffic and limit malware infections; to protect against malicious use, however, intelligent security software is required.  If you want, you can use Priil Ultimate protection that blocks ads on your system and track any suspicious activity in order to secure your system. You can also try Priil Ultimate free, if you’re concerned you may have a malware infection. You can also do Google for more security software.

Final Touch

Hey guys! This was the guide about “what is a packet sniffer.”   It’s good if you can monitor your network, online activities and etc. but these benefits can be converted into danger by some online evils. They exploit these benefits to steal your information in order to make money or for some personal or political reasons. Therefore, make sure before you get into these things and understand properly their pros and cons.