A sniffer is a computer program used to monitor and analyze network traffic from one network location to another. A sniffer captures each packet of information, decodes it and gives the owner the ability to view the content.
If a sniffer is used by a trusted person, it is not considered a malicious application because it is used for troubleshooting and monitoring purposes, or to detect network intrusion attempts. However, sniffers can also be used by malicious people who seek to steal the confidential information of the people that are transmitted by them through a network. This information can be very different.
They can include victim authentication names, passwords, bank account details, credit card numbers, identity details, and other valuable data that can be used in dangerous activities.
A sniffer can be installed on any computer connected to a local network. Often you do not have to run in the affected system.
It can easily hide the hacker’s PC and help him steal the necessary information. This technology also requires a person between the sender of the package and the container. However, a sniffer can be installed in a compromised computer to intercept network traffic and cause other activities. A sniffer can also be a physical device, usually a specific router with interceptive abilities.
It works in the same manner as a normal sniffer, but its detection may be more complicated. As a conclusion, sniffers are divided into legitimate applications and tools designed by hackers specifically to steal personal information and other activities. Both legitimate and malicious sniffer are considered to be very similar programs that can be used for the same purpose.
The only difference is that malicious sniffers are usually specialized tools with non-standard functions. A sniffer does not try to infect the system with other threats. Also, it can not cause performance or stability problems or pose a risk to data stored on your computer.
Even so, a malicious version of sniffer can easily cause activities associated with privacy. This program does not require a lot of system resources and does not have a graphical user interface (GUI), so it’s very difficult to detect when it’s in the computer.
As long as they are in the system, they can be used by hackers to violate the privacy of the victim. Tracking on her back can be done months or even years until she’s noticed. All this time, a sniffer is used to provide the attacker with all the information he needs.
He will be able to discover passwords, login names, contacts, identity data, even credit card numbers and much more. All this information can be used to break the system, steal or disclose the user’s confidential data.
As a conclusion, these are the most important activities needed by sniffer developers to achieve their goals:
1. Monitoring user use of the network and filtering defined packages.
2. Capture all network packets transmitted from one network location to another.
3. Write the data found in the captured packets and save them in a file.
4. Allow the attacker to analyze the data found to discover authentication names, passwords, credit card numbers, identification details, and other valuable information.
Sniffer are not viruses, so they can not propagate and be controlled by certain people. They can be installed like any other program with or without user consent. There are two major ways that unsolicited sniffers can enter the system.