What is VoIP hacking? 5 Signs your business should be aware of

Tom Grange
By Tom Grange, Director of Connectivity

No matter how big your business is or whether you’ve been operating for five years or five months, one thing is for sure; communication is key. 

VoIP — otherwise known as Voice over Internet Protocol — has helped revolutionise how businesses communicate internally and externally. But while they have tremendous advantages, they leave your business vulnerable to hackers, which can be the difference between your business staying afloat or sinking where you stand. 

To help protect your business from a VoIP attack, we’ve put together this handy guide that helps outline some telltale signs and a few simple ways to keep your business secure online.

businessman sat at a desk with his head in his hands in front of hacked computer screens

30-second summary

  • VoIP hacking is a cyber attack that targets a VoIP system in order to get access to a business phone system. Hackers can listen to phone calls, make calls and steal confidential information and customer data.
  • Businesses, governments, service providers and call centres are all likely to be at risk but anyone who has a VoIP system may be vulnerable to an attack.
  • Types of VoIP hacking include eavesdropping, spoofing, VoIP phishing, DDoS attacks and MitM.
  • Signs your system has been hacked include strange call patterns and charges, call quality issues, unauthorised access and strange network activity
  • There are various ways you can protect your VoIP system including using a VPN, using strong passwords and choosing a reputable provider.

What is VoIP hacking?

As you might have guessed, VoIP hacking is where a cybercriminal targets a VoIP system through the internet in an attempt to gain unauthorised access to a business's phone system.

This can wreak havoc on small businesses, as the hacker can cause significant damage as they’re able to:

  • Listen to phone calls
  • Make unauthorised calls using VoIP systems resulting in a surge in telephone bills
  • Steal confidential and sensitive business information
  • Steal customer data, including their email, phone number and other personal information

Find out more about the tactics cybercriminals use with our guide to how to know if your business has been hacked.

How do the hacks take place?

Hackers will mainly try and target VoIP customer service centres and Network Operation Centres as these are easier to manipulate due to their size.

The hacker will pose as a customer or just someone that needs assistance and then trick the phone operator into revealing potentially sensitive information in order for them to gain access, or keep them on the phone long enough to infiltrate their servers. 

Who is at risk of a VoIP hack?

It doesn’t matter who you are or what type of business you run; if you have a VoIP system, you could be at risk of an attack. 

  • Businesses — VoIP is widely used in business environments, making them a prime target for hackers. Organisations of any size can be at risk — including small businesses. Hackers may target companies to gain access to sensitive information, disrupt operations or initiate financial fraud.
  • Government entities — Government agencies and institutions that rely on VoIP for internal communications or public services can be easily targeted. Hackers may attempt to gain unauthorised access to classified information, disrupt government operations, or intercept sensitive communications.
  • Service providers — Service providers who offer VoIP can themselves be at risk of hacking. Attackers may target their infrastructure to collect user information, launch attacks on clients or gain access to customer databases and use this against the provider.
  • Call centres — Call centres that handle customer interactions over the phone can be vulnerable to hacking attempts. Depending on the type of business, hackers may manipulate call recordings, access customer data and disrupt normal operations.
  • Critical infrastructure providers — Critical infrastructure sectors, such as telecommunications, energy, transportation, and healthcare, often rely on VoIP for internal and external communications. Hackers targeting these sectors may aim to disrupt services, compromise sensitive systems, or cause widespread chaos.
  • Individuals — While the primary focus of VoIP hacking may be on businesses and organisations, individuals who use VoIP services are not entirely immune. Individual users can be targeted for various reasons, such as identity theft, financial fraud, or harassment.

Anyone using VoIP services can potentially be at risk of hacking. While the motivations and targets may vary, the increasing adoption of VoIP technology makes it much easier for cybercriminals to target a wide range of businesses and organisations.

What are the different types of VoIP hacking?

Since VoIP phone systems work primarily over the internet, the immense threat and network security issues they are exposed to are relatively different from the traditional methods previously used with other forms of hacking. 

Some of the most common methods used for VoIP hacking include:

  • Eavesdropping — Hackers don’t necessarily have to get access to passwords to be able to gain private information. Sometimes, they’ll simply listen in to conversations for reasons such as corporate espionage, theft and more. They can then sell this information or bribe businesses and customers by threatening to expose their private information.
  • Spoofing — Once a hacker infiltrates the system, they can call other people within the network, impersonating extensions within the business. This can be extremely easy to manipulate with new hires who think they could be talking to the CEO or department head, meaning they’re more likely to hand over passwords or vital information if they believe it’s someone they can trust. 
  • VoIP Phishing — Phishing attacks targeting VoIP systems aim to trick users into revealing sensitive information, such as login credentials or financial details. Attackers may impersonate legitimate VoIP service providers or send fraudulent messages, prompting users to disclose their information, which can be used for unauthorised access or other malicious purposes. Find out more about phishing and the effects it can have on your business with our guide
  • Distributed Denial of Service (DDoS) attacks — Attackers may launch DDoS attacks against a VoIP system to disrupt availability and prevent users from making or receiving calls. By flooding the system with excessive traffic or exploiting vulnerabilities, they can overwhelm the network infrastructure, leading to service outages or severe degradation of call quality. Don’t want to get caught out? Check out our guide to DDoS attacks to keep your business secure.
  • Man-in-the-Middle (MitM) attacks — A MitM is an attack where a hacker intercepts and potentially alters the communication between two parties engaged in a VoIP call. In this attack, the hacker positions themselves between the caller and the recipient, effectively becoming an intermediary, or ’man in the middle’, of the communication.

What are the signs your VoIP system has been hacked?

If you suspect your VoIP system has been hacked, there are some common telltale signs.

Unusual call patterns

Pay attention to any abnormal call patterns within your VoIP system. This could include a sudden increase in the number of calls made or received, particularly during odd hours or outside of typical work patterns. 

Call quality issues

If you experience sudden and persistent call quality problems, it could indicate a VoIP system hack. Hackers might manipulate the system settings, introduce malicious elements, or compromise network infrastructure, leading to issues like echoes, static, dropped calls, or unusually long call setup times.

Unauthorised access

Detecting signs of unauthorised access is crucial in identifying a VoIP system breach. Look for any evidence of compromised user accounts, such as unknown or newly created accounts, unexpected user privileges changes, or unauthorised user settings modifications. 

Weak passwords, stolen credentials, or vulnerabilities in your system's security can allow hackers to access and potentially control your VoIP infrastructure.

Strange network activity

Monitor your network traffic and analyse the data related to your VoIP system. Look for any unusual or suspicious network activity that may indicate something has been compromised. This could include unexpected data spikes, unusual data transfer patterns, or increased network bandwidth usage. 

Attackers will exploit your VoIP system to launch additional attacks internally and externally, use it as a platform for spreading malware, or engage in other malicious activities that generate abnormal network behaviour.

Get to know the effect of online attacks on small businesses with our guide

Unauthorised charges

Regularly review your VoIP service bills to ensure they accurately reflect your usage. If you notice unexpected and unexplained charges, it could be a sign that your VoIP system has been hacked. 

Hackers can make costly international or premium-rate calls using your account once they’ve got in. Make sure to monitor your billing statements for any discrepancies, especially related to call destinations, durations, or charges that exceed your typical usage patterns.

What are the implications of a VoIP hack on a business?

Once hackers have gained access to your VoIP system, it’s easy for them to launch other attacks and compromise the integrity of your business's systems — which can leave your company in serious trouble. 

Depending on the nature of your business and the data involved, a VoIP hack may trigger legal and regulatory obligations. For example, if the hacked data includes personally identifiable information (PII) — which is simply information that when used alone or with other data, can identify an individual — subject to data protection laws, you may be required to report the breach to the Information Comissioner’s Office (ICO). This can then result in investigations, fines and legal action from victims.

A VoIP hack can also harm a business's reputation beyond repair. If customers or clients become aware of a security breach or unauthorised access to their accounts, they’ll lose confidence and trust in the business's ability to protect their private information.

How to protect your VoIP system from hacking

Luckily, there are a few ways that you can protect your small business from a VoIP hack.

Use a VPN

If you have staff that work remotely, in the interest of security, it could be a good idea to install a VPN — also known as a virtual private network — on their devices. 

VPNs help to ensure a strong connection between remote devices and office systems, making it harder for hackers to gain control. It’s also important to make sure that any workers avoid using public WiFi networks, as this makes it easier for hackers.

Use strong passwords and make sure they’re changed regularly

When you set up the VoIP system, it should come with a default password from the provider to start you off. But it’s best to change this ASAP. 

For both yourself and your employees, it’s best to implement strong passwords. These passwords should be a combination of upper and lowercase letters, numbers and symbols. Make sure that no one is using a password that can be easily guessed, such as ‘password123’, and that it isn’t duplicated across multiple devices. 

It’s better to be safe than sorry, so update passwords regularly.

Regularly update firmware

Some avoidable hackings occur simply because businesses are lax in updating their operating systems and firmware. 

These updates shouldn’t take a long amount of time, and keeping them up to date can prevent your business from suffering from a VoIP hacking attack.

Choose the right VoIP provider

Choosing the right VoIP provider is crucial for your business to succeed. At Bionic, we make tailoring a VoIP digital phone system easy

No matter whether you’re looking for a handset, desktop and mobile option or a combination of them all, we can help you find the right deal for your business. 

Get in touch today on 0808 253 4521 to talk to our friendly team about which VoIP product can help take your business to the next level. 

Protect your business from a VoIP hack

Protecting your business from a VoIP attack can be hard, but if you know the necessary signs and how to deal with them, your business should be in capable hands. 

If you need more help understanding business connectivity, head over to our connectivity guide pages for more information. Or, get in touch today with the Bionic team to discuss your business connectivity needs, including business broadband and VoIP.