Sadly, as advanced as your VoIP setup might be, there will always be malware and hacking risks.
In this guide, we’ll explore the current state of VoIP security worldwide and some of the best practices to protect your infrastructure.
The Growing Landscape and Importance of VoIP Security
More and more businesses are moving to VoIP, and for hackers, that means there are more targets than ever to exploit. The VoIP services market is projected to grow at over 10% CAGR running to 2034 – there’s a lot at stake.
VoIP has brought with it a series of new threats and vulnerabilities that simply didn’t exist via legacy telecommunications. For example, there’s been extensive research undertaken into how hackers can exploit SIP infrastructures – uncovering the potential for call and register flooding and code injections.
These threats are hardly emerging – but, given that countries such as Norway, Germany, and Japan have already switched off legacy PSTN – and that the UK and US are transitioning to VoIP en masse – they’re threats that are becoming increasingly obvious to the global populace.
It pays to be proactive and vigilant – for example, by running external penetration testing to analyze how secure your infrastructure is from the outside.
What’s more, it’s becoming increasingly important to learn about common threats and emerging vectors as VoIP becomes the default telecommunications standard.
Common VoIP Security Threats
As we explored in our guide to how to spot VoIP cybersecurity problems, there are various ways bad actors can exploit your systems. Let’s quickly recap:
- Call flooding, where attackers prevent SIP devices from operating by overloading them with invitations and requests.
- Phishing, where attackers exploit your caller ID to seize information from unaware personnel.
- Eavesdropping, where hackers intercept private conversations on VoIP to gain sensitive data.
- Man in the Middle or MITM attacking, where attackers intercept VoIP calls or introduce malware into a stream of communication.
- Phreaking, where criminals break into VoIP systems through reverse-engineering, running up costs by leeching functionality, and stealing sensitive data.
- SPIT, or Spam over Internet Telephony, where attackers clog up VoIP voicemail.
- VOMIT, or Voice Over Misconfigured Internet Telephone, where hackers record calls and use them to obtain data and create social engineering campaigns.
Emerging Threats in VoIP Security
Alongside the common threats and vulnerabilities listed above, there are worrying trends emerging that not all VoIP users might be prepared for:
- App trojanizing: Where attackers create malicious versions of popular software. An example within VoIP is the 3CXDesktop App, which was cloned and offered up malware to create hacker beacons.
- Distributed denial of service attacks (DDoS): Overloading VoIP systems until they crash is becoming more and more commonplace, increasing by 112% year on year. Recent large-scale attacks in Japan show that attackers are also targeting IoT (internet of things) devices by installing malicious botnets.
- Cloud-focused attacks: Research suggests hackers are growing more confident and capable of mounting cloud attacks on VoIP businesses, with 40% of all attacks taking place across several locations at once.
- Provider security failures: Some lesser-prepared VoIP providers are continuing to pass on security threats and, therefore, data loss risk, to their customers.
- AI keystroking: By using artificial intelligence, VoIP hackers can now analyze keystroke data faster than ever to steal data and publish reports. Tools using such techniques report up to 93% capture accuracy (and improving).
- Password forcing: 88% of companies still use basic passwords to safeguard their systems, and as many as 40,000 out of 1.8 million admin passwords are simply “admin.” Hackers can force millions of password guesses per second using tools.
Best Practices for Securing VoIP Systems
Some of the best practices we recommend for securing VoIP systems include:
- Updating software regularly and often: Don’t just update software when you remember to – set a regular schedule to make sure your programs are patched and free from potential backdoors.
- Reporting faulty equipment: If you notice hardware such as desktop phones, microphones, and/or webcams behaving strangely, report them to a specialist. These could be flags for attackers using your tools to spy on your company. Install the latest firmware patches whenever they become available.
- Using secure connections: Unsecured and public WiFi remains a major attack route, with around a quarter of US adults experiencing data compromise through public connections. If you provide remote VoIP access to off-site employees, always insist they connect through WPA3-encrypted routers.
- Retraining your team: Regularly refresh and test their knowledge to better safeguard your data – doing so helps to improve their awareness of phishing techniques, too.
- Taking note of call quality: If your call quality drops unexpectedly, there’s a chance attackers are draining your resources by congesting your network.
- Being selective with third-party services: Any vendors you work with in the cloud also need to be secured against evolving threats – otherwise, there could be routes in for hackers to attack your systems, too.
- Running penetration tests: Penetration testing helps you gain a complete oversight of your VoIP systems’ security posture. This type of security analysis mimics typical hacking attempts to expose vulnerabilities and exploit them in controlled environments. We recommend pen testing systems at least twice a year.
- Monitoring your VoIP activity: Always check calls and charges – unexpected call patterns and inflated bills can suggest hackers are silently using your network and expecting you to pay for the privilege.
- Establishing multi-factor authentication. As explored in our guide to securing SIP, MFA strategies are simple yet effective in deterring would-be password thieves.
Preparing for Future Challenges
Unfortunately, there’s no real way of knowing what threats will look like in the years to come, which is why many businesses using VoIP partner with cybersecurity professionals to run regular tests and monitor their systems.
This way, they’re better protected against the latest in GenAI attack trends that seem to be evolving by the minute. In fact, one of the best strategies against AI threats is to fight fire with fire – to use AI-enhanced security to prevent automated data theft!
Conclusion
Strengthening VoIP systems could be as simple as rethinking your authentication strategies, working with cybersecurity experts, and being more selective with vendors. The bottom line is to regularly update, patch, and test your systems – you never know what’s lurking out there.




















