Why Do Telephone and VoIP Attacks Continue?

Voice over Internet Protocol (VoIP) systems operate through a robust centralized internet connection, delivering calls and information over IP networks. This makes businesses that use VoIP especially vulnerable to cyber security threats and attacks. Despite these risks, there’s a silver lining: reliable connections, significant cost savings, and internalized communication are some of the advantages of switching to a VoIP system… but there are still some other things to consider when it comes to security.

A 2018 report by Blueface found that 35% of businesses used VoIP, and 25% considered switching from a public switched telephone network (PSTN) which is the same as traditional phone service. With the recent rise of cyber attacks across business networks, it means that cyber security will continue to be a concern with VoIP systems.

Types of VoIP Attacks

Cyber criminals look for any entry point into a company’s network to launch an attack, and since VoIP runs on a business’s network, specific attacks are built to attack the VoIP system.

Denial of Service (DoS) Attack

A Denial of Service (DoS) attack is a hostile attempt to interrupt the regular traffic of a targeted VoIP network. This is done by flooding the servers with incomplete requests, taking over the entirety of the server’s bandwidth. This causes the network to slow down, or possibly shut down altogether, and is most commonly used for jeopardizing the 911 phone lines and hospital hotlines. During a DoS attack, hackers will most likely demand a ransom to stop the attacks. Attackers make it nearly impossible to identify them by using different kinds of DoS attacks such as call flooding, malformed messages, and caller ID spoofing.

Viruses and Malware

Neither of these insidious tech maladies should be news to anyone at this point. We all know companies need to remain vigilant and protect themselves from viruses and malware which may infiltrate a network system. VoIP networks are no different. They run softphones such as Skype or Zoom Phone, and hackers will use these platforms to steal data and take over networks. Making sure that these platforms are updated and protected is critical to keeping a company’s network protected.


Vishing is a tactic that cyber criminals use to target the user instead of software or hardware. Just like phishing emails, hackers trick employees into providing credentials or sensitive information, but instead they do it over the phone. Callers pretend to be from a reputable company to get personal information, passwords, bank details, or credit card numbers.


Attackers will access unsecured networks to intercept unencrypted VoIP calls and listen to them. They can gain sensitive business information, employee details, account numbers, phone numbers, and any other information that may be disclosed.

Toll Fraud

Controlling the PBX is vital for this method to work. Typically, toll fraud requires outside line access, and from there, costly international numbers are dialed.  Charges for those calls are then billed to the company instead of the person making the call.

SPIT – Spam Over Internet Technology

SPIT is the phone variation of spamming. It typically shows up as a voicemail or “robocalls.” Answering one of these calls or listening to a voicemail may redirect the targeted user to a different country, costing the company money or may transfer a virus to the company network.

Tips for Improving the Security of VoIP Systems

VoIP attacks can be extremely harmful to any business, but they can be averted by improving the security of your VoIP network using these simple tips:

  1. Monitor VoIP traffic 24/7. Most VoIP security breaches happen after operating hours because system monitoring is nonexistent or minimal. Some attack attempts can be identified beforehand by noticing the abnormalities in the traffic. It can be expensive for small businesses to hire 24/7 full-time IT staff but using a managed security services provider can provide the additional monitoring required.
  2. Use encryption tools. A VoIP system without security encryption can be broken into even by amateur hackers. In addition to giving attackers a way into a corporate business system, a gap in the telephone network can create distrust with customers and a decrease in sales. Investing in encryption tools can create a safeguard against eavesdropping attacks.
  3. Create a virtual private network (VPN). Apart from the encryption tools, small- and medium-sized businesses that operate on VoIP networks can enhance their security by establishing a virtual private connection (VPN). VPNs produce a protected connection between you and the caller if they are on a similar connection.
  4. Enable Network Address Translation (NAT). NAT is a router feature that provides phones, laptops, and other devices a private IP address that only the corporate Local Area Network (LAN) can see. Without knowing the IP address, a hacker can’t access the device remotely, so this provides an additional layer of security.

VoIP technology has been around for many years, but as the technology changes, so do the risks of malicious attacks. Keeping systems updated and initiating safety protocols helps prevent attacks through a business’s VoIP network and is critical to an organization’s overall security plan.

Visual Edge specializes in managed IT services and security, cloud computing, and print/copy solutions for businesses across the U.S., including remote offices. The company has more than 30 years of technology service with a national network of expert engineers. Request your no-obligation assessment today and get a free dark web analysis.