Zero Trust SMS

Zero Trust SMS is a solution to SMS phishing, Flubot, and other malware. Ensure every URL delivered by SMS to every subscriber is safe and secure. The solution verifies every URL in every SMS message to categorise URLs based on Zero Trust methodology and the most comprehensive and advanced database of verified secure URLs, instead of relying on block lists. 

  • Protect your subscribers
  • Protect your brand and reputation
  • Protect SMS as a revenue channel

What is smishing?

SMS phishing is the practice of sending SMS containing a malicious URL to a subscriber. This message might also have a spoofed sender ID or the perpetrator may impersonate another sender. The victim follows the link to a phishing website where they are tricked into entering credentials and other sensitive information. The fraudsters use this information to gain access to other accounts and further defraud the subscriber. 

SMS has an open rate 5X higher than email and is still seen as a more trusted medium, leading to higher click through rates and a more reliable pool of victims.

Why Zero Trust?

A Zero Trust approach relies on the logic that everything that cannot be verified to be trustworthy must be regarded as suspicious. This is a departure from previous security models that rely on allowing traffic as a default and eliminating threats as they are detected. 

“What cannot be verified cannot be trusted.”  

In the Zero Trust SMS system, this means checking every single URL in every single message instead of relying only on blocklists to filter out known malicious URLs. Millions of new domains are registered every day and cannot be immediately verified. URLs that cannot yet be classified are considered potentially dangerous and the subscriber is warned to proceed only with great caution. URLs are not considered innocent until proven guilty, but rather guilty until proven innocent.

Integration with SMS Firewall

Zero Trust SMS can be integrated with or without an SMS firewall. 

With Firewall

Integrated with the Cellusys SMS Firewall or any other SMS Firewall, the Zero Trust SMS system scans all SMS allowed by the firewall for URL links. All URL links are then categorized as either safe, dangerous, or unknown.

SMS Firewalls block messages based on volume and suspicious parameters, however may not be able to detect every kind of smishing attempt such as spear-phishing which targets an individual or a very small number of victims.

The Zero Trust SMS system is a solution for all SMS messages containing URL links. By checking every single SMS, you can be sure to protect every single subscriber from malicious smishing attempts. 


Without a firewall Zero Trust SMS is a complete solution for SMS phishing attacks even in the absence of protection against spam and spoofing (provided by an SMS firewall). Every single SMS message is scanned for URLs, and each URL is classified as safe, dangerous, or unknown.

By blocking all malicious links, and only delivering verified URL links, all subscribers in your network are protected from all potentially harmful phishing links received through SMS messages, regardless of whether they are also spam or use spoofed sending IDs.

How does it work? 

SMS traffic is sent to the ZTSMS system which scans all SMS messages for URLs, including shortened URLs within the message. Each of these URLs is sent to the MetaCert database to be categorised as either safe, dangerous, or unknown. The subscriber receives an alert with each SMS informing them that URL is either verified and safe to proceed; dangerous and has been blocked for their security; or is unable to be verified with instructions to proceed only with extreme caution.

About MetaCert

MetaCert has developed patented, proprietary technology that reduces the risk of all cyber attacks that begin with dangerous URLs by more than 99%. This technology was originally used to protect enterprise employees from phishing domains, and has now been adapted to suit the needs of mobile networks and their subscribers.

User Experience

  • Fully customizable to network requirements
  • Can be whitelabeled to include network branding 
  • Various UI models to choose from
  • User can be redirected from dangerous or unknown links to holding pages

Accessible Reporting

Equipped with powerful (yet agile) reporting and alerting features, not only will your network be secure, you can be sure to have the most accurate information about your network traffic and security at your fingertips.

Customise real-time alerts to be notified the moment a threat occurs.

Everyone on your team can be provided proper access levels and customise reports to suit their individual needs (no matter their level of technical expertise) thanks to the intuitive GUI.

Easily set alerts or publish reports as broad as traffic overview or drill down to monitor a suspicious caller ID. Troubleshoot VIP complaints and monitor message volumes with the touch of a button.

SMS Aggregators

The middle is your business — make it flow. Our A2P solutions have helped many top SMS aggregators to eliminate grey routes, boost volumes, and open the floodgates on A2P revenues for their partner networks.  

Signalling Providers and Signalling Hubs

Signalling is your business — at least make it secure.

We have provided many Tier1 signalling hubs with the capability to control and secure their signalling.

Learn more about

SMS Firewall

How secure is your network?

Learn more about our

Managed Service for Security


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