Mostly used as a packet analyzer by IT professionals to monitor network traffic in real-time, packet sniffing can be a double-edged sword as cybercriminals can also use it to their advantage and steal data.

So is packet sniffing ethical? How does it work? And how can you protect your data from malicious sniffing attacks?

Is Packet Sniffing Ethical?

Similar to wiretapping a phone, packet sniffing allows anyone to eavesdrop on computer conversations. It has both ethical and non-ethical connotations depending on the reasons behind tapping into a network.

Ethical Reasons For Packet Sniffing

Here are some ethical reasons for which packet sniffing can be used.

Monitoring network security: Network administrators rely heavily on packet sniffing to gauge important data regarding the health and security of a network. By collecting the monitoring responses through packet sniffing, they can test the encryption status of HTTPS connections.

Examining unencrypted traffic: It is also used for examining traffic for plain text passwords, usernames, or other data that remains readable so that proper encryption can be implemented.

Troubleshooting and triage: Packet sniffing is a great tool for troubleshooting traffic bottlenecks as well as understanding the usage of most applications.

Checking network status: Network administrators often used packet sniffing to determine the status of devices by observing the responses to network requests.

Ensuring routing and network ports: Packet sniffing can be used to detect any network or port misconfigurations. It also helps ensure that the most correct and efficient route is being selected for DNS requests, etc.

Unethical Reasons For Packet Sniffing

Here's why someone with malicious intent might use packet sniffing.

Gaining unauthorized access: Packet sniffers can be used by cybercriminals to gain illegal access into a network. Most cybercriminals employ phishing scams, social engineering tactics, or malicious email attachments to fool their victims into downloading their packet sniffers.

After gaining entry into a network through a sniffer, cybercriminals can easily access login credentials and other private information by simply monitoring network activity like emails and instant messages sent across the network.

Conducting spoofing attacks: Packet sniffing can be used by hackers to sniff unsecured public Wi-Fi networks and carry out spoofing attacks by impersonating reliable sources.

By employing wireless sniffers and setting up fake access points in public spots such as coffee shops or airports, threat actors can obtain and misuse sensitive data.

TCP session hijacking: A very common type of packet sniffing, Transmission Control Protocol (TCP) session hijacking is a malicious attempt by cybercriminals to hijack network sessions by intercepting packets between the source and destination IP addresses.

By conducting TCP hijacking, sensitive data such as port numbers and TCP sequence numbers can be viewed by the threat actors.

What Is a Packet Sniffer?

data packets

A packet sniffer can be a hardware or software tool that is used for sniffing or intercepting the network.

The hardware part of a packet sniffer is the adapter that connects the sniffer to an existing network. A hardware sniffer must be physically connected to a device or a network to monitor the network flow.

A software-based packet sniffer is interactive and lets you log, observe, and view the collected data. This is the most commonly used method for data sniffing nowadays because instead of physically intercepting the data, software sniffers simply modify the default behavior of the data node that they are installed onto.

How Does a Sniffer Work?

Regular network traffic is composed of data packets traveling from source to destination with no intermediate nodes or interceptions along the way. However, packet sniffing works by changing this default traffic behavior where each packet traveling from source to destination is collected and logged along the way.

A packet sniffer is then used to analyze this collected data and convert it into a human-readable format so it can be further examined by the intercepting entity.

How to Protect Against Sniffing Attacks

secured laptop

Most sniffing attacks carried out by threat actors can be quite stealthy. However, the good news is that there are ways to protect against these attacks.

Here are some common ways to mitigate sniffing attacks.

Install a Robust Antivirus Tool

Since sniffers can be transmitted by hackers in the form of viruses, Trojans, and worms, the best way to protect against them is by investing in a strong antivirus suite.

Look for tools that provide around-the-clock protection to block malware and protect against being affected by malicious attachments, links, and downloads.

Invest in a VPN

The next step in beating sniffing attacks is to encrypt your data. Encryption offers the most robust defense against these attacks because even if your data is sniffed by someone, it will be useless for them since it is encrypted and secured.

Investing in a VPN can help encrypt your data as traffic is made to pass through a secure and encrypted channel over the internet. This makes it hard for anyone to decrypt your intercepted data.

Don't Browse Unencrypted Websites

HTTPS is the secure version of the HTTP protocol. Most secure websites use HTTPS and display a padlock icon next to the URL. These websites are encrypted and relatively safer for you to visit.

Related: Does HTTPS Protect Data in Transit?

Always avoid using unencrypted websites, like the ones starting with "HTTP". However, if you do stumble upon one, avoid entering your personal details or login information.

Avoid Using Public Wi-Fi

A huge number of people connect to public networks in airports, malls, cafes, and other public places. As tempting as it sounds, it's always better to shy away from public internet and free hotspots.

Once you are on a public network, anyone can use a packet sniffer to help themselves to your data. Again, a VPN can help protect you in these situations.

Stay Away From Unencrypted Messaging Apps

Similar to public Wi-Fi, unencrypted messaging apps also pose a risk to your data security and can play a part in a sniffing attack. Always use reliable messaging apps like WhatsApp, Viber, and Telegram, since they offer end-to-end encryption.

Protect Against Sniffing Attacks

encrypted text

Packet sniffing is not always bad news but if used for malicious reasons, it can turn into a complex hacking tool that can be very challenging to notice. Most ordinary users cannot detect that they are being sniffed, making the practice all the more dangerous.

However, all is not lost. Always remember that encryption is your best friend in the war against cybercriminals. By investing in strong encryption and security policies, these sneaky packet sniffers can be stopped from intercepting your sensitive data.