Services Blog

A Hacking Threat Vector That Goes Overlooked: Your VoIP Phone System

Written by Jason Blalock | Jun 22, 2017 12:55:00 PM

If there's one rule of online crime today, it's that if something is online, criminals are looking for ways to subvert it.  So when developing security systems for a network, it's vital to address every possible vector for attack.  Unfortunately, one key system often goes forgotten during security reviews, and that can mean very bad news for businesses: a VoIP phone system.

It's easy to take a telephone system for granted, but hackers are coming up with new ways to exploit VoIP systems all the time.  The threats presented by phone-based hacking are every bit as serious as other attack types.

What Hackers Can Do If They Gain Access To Your VoIP Phone System

There are a surprising number of ways a VoIP system can be subverted.  For example:

Toll Fraud:  Having gained access to your VoIP lines, the criminals then become their own private phone company - with you paying the bill.  They'll often even resell your service for their profit.

Spamnets:  Much like how a compromised computer can become part of a botnet spreading email spam, a compromised VoIP system can be used to spread voice spam - potentially even getting you into legal trouble under Do-Not-Call legislation.

Eavesdropping:  Any and all private or confidential information discussed over your phones can be captured and used against you.

Voice Phishing:  Having direct access to your VoIP system makes it easier for criminals to spoof (falsify) calls from seemingly-genuine sources, for the sake of gaining confidential information.

DDOS Attacks:  If attackers want to cripple your business, directly targeting a SIP server is a great way to do it, particularly since they usually don't have robust anti-DDOS protections.

Not to mention, in many cases, gaining access to a company's VoIP system ultimately allows attackers to gain access to other critical systems.  So a VoIP attack also presents all the same threats as any other network\data attack.

It's important to note that these concerns are valid whether you're receiving VoIP from a third party provider, or you run your own SIP and PBX interface on-site.  However, if you're doing everything on site, you're probably at higher risk.

Protecting Yourself From VoIP-Based Attacks

Largely, security for a VoIP system is the same as for any other major part of your network.  The problem is that so many businesses forget to give it suitable protections.  In particular:

1 - Always change the default passwords.

This should go without saying, except you'd be surprised how many businesses don't bother.

2 - Have discrete logins for any admin who controls the system.

Never share usernames and passwords between administrators.  Everyone should have unique credentials.

3 - Deploy anti-virus and anti-malware software.

Yes, there are software packages and network architectures which can provide antivirus protections to your phones too.

4 - Utilize Session Border Controllers

SBCs guard the edge of your network, such as where your VoIP system interfaces with the networks outside your building.  They're like firewalls for your VoIP.

5 - Password-protected phone calls.

It's a bit of a pain for your workforce, but will greatly reduce the ability of someone to make calls even if they gain access to your system.

6 - Always review call logs.

Regularly go over all your logs and look for any anomalies, particularly out-of-country calls to areas you don't do business in.

7 - Implement Secure Real-Time Transport Protocol (SRTP)

SRTP is end-to-end encryption on VoIP calls.  It can degrade call quality somewhat, but in many cases - particularly if you deal in sensitive information - it's a worthwhile trade off.

Are you concerned about your on-site security?  Contact Hummingbird Networks today to request a free consultation on your security measures!