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What are eavesdropping attacks?

Author: Mark Stone

Eavesdropping attacks happen when cyber criminals or attackers listen in to network traffic traveling over computers, servers, mobile devices and Internet of Things (IoT) devices. Network eavesdropping, also known as network snooping or sniffing, occurs when malicious actors exploit insecure or vulnerable networks to read or steal data as it travels between two devices. Eavesdropping is most common for wireless communication.

Here's a closer look at eavesdropping attacks and how to guard against them.

How do eavesdropping attacks work?

Eavesdropping attacks are made possible when a connection between two endpoints (think a client and server) is weak or not secure. Insecure network connections exist when encryption isn't used, when applications or devices aren't up to date, or when malware is present.

With an insecure network connection—typically a Wi-Fi hotspot or websites not running the HTTPS protocol—data packets traveling across the network could be intercepted. That data might be your web, email or messaging traffic or any confidential corporate data.

But how do hackers "sniff" this data? Many legitimate sniffer programs were created for network monitoring and vulnerability management and to be used by security teams. Of course, these applications can also be exploited for nefarious purposes by cyber criminals.

Sophisticated attackers use social engineering methods like phishing to install malware and sniffing programs onto victims' networks.

Understanding the risks

The goal of eavesdropping attacks is simple: steal confidential and valuable data by peeking at insecure or unencrypted traffic.

For attackers, the potential bounty from an eavesdropping attack can be significant. Up for grabs is anything from credit card information to personally identifiable information (PII), customer or employee passwords, and intellectual property. With the rise of IoT, more devices are on business networks than ever before.

How to protect your company

Detecting eavesdropping attacks is challenging. A proactive approach is therefore critical for eavesdropping attack prevention.

The most common form of protection against eavesdropping is a virtual private network (VPN), which encrypts data between two points. Applying the highest form of encryption possible for corporate wireless networks and using HTTPS for all web-based communication is recommended.  According to the 2021 Data Breach Investigations Report, organizations that neglected to implement multi-factor authentication, along with virtual private networks (VPN), represented a significant percentage of victims targeted during the pandemic.

For most companies, VPN and HTTPS are the minimum standards.  To better protect against eavesdropping (and many other attacks, for that matter), your organization must consider the following additional cyber security best practices.

  • Authentication. Make sure your IT or security teams use some form of authentication for incoming network packets. Standards and cryptographic protocols include S/MIME (Secure/Multipurpose Internet Mail Extensions), TLS (Transport Layer Security), IPsec (Internet Protocol Security) and OpenPGP.
  • Network monitoring. Monitoring your networks for abnormal activity or traffic is an essential cyber security best practice. Deploying intrusion detection systems and endpoint detection and response solutions can simplify this process. Security teams may also want to use the same eavesdropping software as attackers to detect vulnerabilities.
  • Cyber security awareness. Many eavesdropping attacks are launched because an employee clicked on a link in an email. That link installed the malware, which made it all possible. Educating employees about the risks of phishing and how to avoid becoming a victim is crucial.
  • Network segmentation. This process partitions the network into separate segments so traffic cannot flow from one segment to the next. For example, computers connecting to a network containing critical data will be unreachable to people or computers connected to a network with general office documents or other data. If one network segment is compromised, the hacker won't be able to infiltrate into others.

Fostering a cyber security culture with a robust and engaging training program may be the best form of prevention. Make sure your program encourages strong password use, defeating phishing and discourages the use of public Wi-Fi networks without a proven VPN solution.

Learn more about how Verizon can help protect your business with VPN end-to-end encryption.