Vishing and SPIT: A Guide to VoIP Security Threats

Your voice traffic is digital data, and it is subject to many of the same hazards other data faces once it leaves your network. As VoIP has moved from a niche option to a mainstream way to run a business phone system, it has also picked up a vocabulary of security threats worth knowing.

The first mass produced automobiles started rolling off the assembly lines in the early 1900s, but it took a couple of decades before door locks were regularly installed on vehicles. Previously, there was no need to secure them.

Necessity is the mother of invention. Keeping VoIP secure was not a concern when it was first introduced. Providers and customers were far more concerned about cost and reliability. Now that those two factors have been nailed down and VoIP has become a mainstream communication option, organizations have discovered it is time to put some locks on it. Here is a look at some of the threats VoIP users can face.

Vishing

We are already used to phishing. Now we have to prepare ourselves for vishing. The most common version of this is tampering with the caller ID. Someone could set themselves up to look like your bank or another trusted organization. With VoIP, a visher can potentially send one message to thousands of recipients at the same time, creating a virtual number that can disappear without leaving any trace.

It is not necessarily your VoIP system that is at risk. It is your users. Any type of phishing that has been used in email can be duplicated using VoIP. Are you really sure it is your bank calling just because you see their name on the caller ID? Never provide sensitive information over the phone, whether it is via VoIP or otherwise.

Service theft

VoIP services can be stolen with a valid set of credentials, and hackers try to obtain these by eavesdropping. Once they have credentials for your VoIP network, they can make calls without paying, but that is usually not why they go through the trouble of eavesdropping. They are more interested in gaining access to confidential information that might be stored in voicemail.

SPIT

Move over spam. VoIP is joining the party, and the flavor is called SPIT, which is an acronym for Spamming over Internet Telephony. You have a voicemail, but it is spam. This is a developing problem for some organizations using VoIP platforms.

Every VoIP account has an associated unique IP address. Once obtained, spammers could send messages to an improperly secured voicemail. They can send a single spam voicemail message to thousands of IP addresses at the same time. This is a nuisance, and it can also become an expense, as more space is needed to store this digital spam data.

DDoS attacks

Remember that VoIP telephony requires the internet. A hacker with an axe to grind might try to carry out a Distributed Denial of Service (DDoS) attack by flooding your VoIP network with unnecessary SIP call signaling messages. Your service would be degraded. Why would they do this? Well, why do websites suffer from DDoS attacks? Sometimes somebody out there just does not like you.

How to keep your VoIP secure

This all may sound scary, but it does not have to be with strong security in place. VoIP security is only as reliable as the network that supports it. It is your provider's responsibility to handle much of the protection that comes from being vigilant about gateway security, firewall configuration, wireless security, and system logins. Keeping some of that information safe on your end is your responsibility.

Know what the threats are and how to guard against them. Your VoIP provider is your partner. They will do most of the heavy lifting, but it is still important that your people know what to look out for. For a deeper look at the protections that should sit underneath your phone service, see our guide on VoIP security measures that safeguard your conversations, and review the rest of our security and IT articles for more ways to stay ahead of attackers.

A reliable provider matters because security starts with the network. CallSprout runs a cloud business phone system on a 99.999% uptime network, so your calls stay up and your data stays protected even when someone is trying to disrupt them. Our AI Voice Agent answers, transcribes, and routes calls for you, which means fewer voicemails sitting around as targets for spam and a clear, searchable record of every conversation.

Ready to put real locks on your phone system? Learn more about our network reliability or contact our team to talk through securing your business communications.