An eavesdropping attack occurs when cybercriminals steal information sent or received by a user over an unsecured network. It is also known as a “sniffing attack” and can come in different forms.

The use of the two terms “eavesdropping” and “sniffing” makes the attack seemingly mild but attackers actually do more than eavesdrop or sniff. Victims of an eavesdropping attack could suffer severe losses, as eavesdroppers could obtain sensitive information that they can sell for malicious purposes. 

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Read More about an “Eavesdropping Attack

eavesdropping attack

An eavesdropping attack is a passive form of a cyber attack, making it difficult to detect. An eavesdropping software could be inserted in a compromised device and sit there undetected since it does not alter how the network works.

Because an eavesdropping attack is difficult to detect, attackers can get hold of sensitive information, including victims’ call logs, messages, credit card numbers, and login credentials. The software attackers use can also detect communication patterns like call volume and frequency to specific people or numbers.

The theft of these sensitive details can result in account takeovers, identity theft, and financial damage. Attackers also stand to gain more by selling the stolen personal information on the Dark Web.

Eavesdropping Attacks: How Attackers Listen In

An eavesdropping attack starts with a piece of malware that allows attackers to plant the eavesdropping software or the packet sniffer on victims’ computers. The malware could enter devices when users click a malicious link in a phishing email. It could also be obtained by downloading infected software or applications. The sniffer could also be planted on an unsecured network.

The attackers can then monitor the software or preprogram it to send the data automatically. A hypothetical scenario that is not too far-fetched is this: A payroll officer was at the airport when he remembered he needed to send the company’s payroll report to his manager. He connected to the airport’s open Wi-Fi network and emailed the report. Unbeknownst to the payroll officer, an attacker was able to intercept the email and download the report that contains attendance logs and employees’ banking information.

An eavesdropping attack can also make way for man-in-the-middle (MitM) attacks where threat actors can modify messages and impersonate one of the communicating parties. In our hypothetical scenario, the attackers could alter the message and enter their bank details, so the payroll payments go to them.

Avoiding an Eavesdropping Attack: Best Practices

Avoiding eavesdropping attacks calls for several tried-and-tested cybersecurity measures, including the following:

  • Do not connect to unsecured networks, especially when conducting sensitive transactions, as attackers can easily exploit them. As much as possible, avoid connecting to open Wi-Fi networks available in airports, coffee shops, and hotels.
  • Use different passwords for every account and change them regularly. That way, even when attackers get hold of one of your passwords, they won’t be able to take over your other accounts.
  • Use military-grade encryption (256-bit), so even if an eavesdropping attack occurs, attackers won’t be able to see the encrypted data. Using virtual private networks (VPNs) is one way to encrypt your network traffic.
  • For organizations, network segmentation or dividing the network so each department has different access rights may help. The sales team, for example, does not need access to the payroll system.

An eavesdropping attack is more than having someone listening in to your online transactions and conversations. Victims can suffer exponential damage and even run the risk of having their identities and privacy exploited. The attack is also relatively easy for cybercriminals to execute, especially when users do not practice good cybersecurity habits.