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. It's worth noting, however, that these analyzers can also be used for malicious purposes. 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. 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. 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. 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. 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. 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. Next is 'filtered' mode, meaning analyzers will only capture packets that contain specific data elements. The first is 'unfiltered,' meaning they will capture all packets possible and write them to a local hard drive for later examination. It's possible to configure sniffers in two ways.

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. 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. 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.

Packet capturing tool