A phishing email lands safely in a crew member’s inbox. It passes every security check. Hours later, if an unsuspecting crew member clicks the link, the attack begins.
This increasingly common tactic is one reason why modern email security must extend beyond the point of delivery.
Modern vessels rely heavily on email for operational coordination, vendor communication and crew welfare. This connectivity improves efficiency but it also expands the attack surface available to cyber criminals.
Email remains the primary delivery method for phishing attacks and credential theft, making it one of the most significant cyber risks facing both shoreside organisations and vessels. The challenge is not just technical filtering of messages but managing the risks introduced when users interact with content inside those messages.
One of the most persistent threats is the malicious web link. A link that appears safe when it arrives in an inbox can later be weaponised. This creates a gap in traditional email security controls and it is a risk that must now be addressed as part of a layered maritime cyber defence strategy.
Our new Link Check feature within GT Mail is designed to close that gap by providing time of click protection for links contained within email messages.
The Regulatory Context
Cybersecurity is no longer treated as an optional technical enhancement in shipping. It is increasingly embedded within regulatory frameworks and operational governance.
Several developments highlight this shift;
- The IMO requirement for cyber risk management within Safety Management Systems under the ISM Code
- Increasing scrutiny from flag states and classification societies
- IACS Unified Requirement E26 addressing cyber resilience in shipboard systems
- Industry guidance from BIMCO and other maritime organisations
These frameworks emphasise risk identification, layered protection and operational resilience. Email security plays a direct role in supporting these objectives because compromised communications can affect both IT and operational technology environments.
A malicious link that leads to credential theft, malware download or ransomware deployment can quickly escalate from a simple phishing attempt into a wider operational disruption.
From a compliance and assurance standpoint organisations must therefore demonstrate that reasonable preventative controls are in place.
The Delayed Threat Problem
Email perimeter security checks inspect links at the point a message is received.
This typically includes:
- Antivirus scanning of attachments
- Reputation checks against known malicious domains
- Malware sandboxing where suspicious files are evaluated in a controlled environment
GT Mail performs these controls within the cloud to ensure threats are identified before messages reach vessel systems.
However, attackers increasingly exploit a timing gap. A phishing email may contain a legitimate web link that passes initial security checks. Hours or days later the attacker changes the destination content behind that link to deliver a malicious payload.
The message appears safe when delivered but the risk only emerges when a crew member clicks the link.
For this reason, effective cyber defence relies on layered protection. Within GT Mail this begins with perimeter security controls including SPF, DKIM and DMARC authentication checks, real time blacklist validation, antivirus inspection, malware sandboxing, phishing detection as well as Link Check giving time of click protection.
Time of Click Protection with Link Check
Link Check within GT Mail addresses this problem by extending protection beyond the point of message delivery.
When an email passes through GT Mail the system rewrites embedded web links so that they route through the GTMaritime security platform if clicked.
If a user clicks the link, the system performs a real time security inspection before allowing the connection to proceed.
This process enables several important protections:
- Verification of the destination URL at the moment of access
- Blocking of links that have become malicious after delivery
- Protection against newly discovered phishing domains
- Logging and visibility of suspicious link activity
From a cybersecurity perspective this introduces an important additional control layer. The link is validated at the moment it is used rather than only when the message was received.
Supporting the Human Firewall
Even the most advanced email security cannot remove people from the cybersecurity equation. Crew members will continue to receive emails that require judgement, and attackers deliberately design messages to exploit trust, curiosity and urgency.
Technical safeguards such as Link Check provide an important safety net by reducing the likelihood that a single mistaken click becomes a serious security incident. However, technology is only one layer of an effective cyber defence strategy.
Building a strong human firewall means equipping crews with the knowledge and confidence to recognise suspicious emails before they interact with them. Security awareness training helps users understand the techniques used by attackers, recognise common phishing indicators and develop safer online behaviours.
This is where GT Aware complements GT Mail. By combining continuous security awareness training with technical controls such as Link Check, organisations can reduce both the likelihood of a successful phishing attack and its potential impact. Users become better at identifying threats, while Link Check provides an additional layer of protection should a malicious link still be clicked.
Ultimately, the strongest maritime cyber defences combine informed people with intelligent technology, because neither layer is sufficient on its own.
Conclusion
Cybersecurity in maritime operations depends on layered protection that combines technology process and crew awareness.
Email filtering, antivirus inspection and malware sandboxing provide strong preventative controls. However modern phishing campaigns increasingly exploit the delay between message delivery and user interaction. Time of click protection closes that gap. By validating links at the moment they are accessed, Link Check strengthens the resilience of vessel communications and reduces the risk that a routine email interaction becomes the starting point of a wider cyber incident.
In maritime cybersecurity the objective is not simply to stop threats at the gate. It is to ensure that protection continues throughout the entire voyage of the data.
As phishing techniques continue to evolve, maritime organisations need security that adapts with them. By combining preventative email security, time-of-click protection through Link Check and user awareness with GT Aware, GTMaritime helps operators build the layered cyber resilience expected by today’s regulatory landscape and tomorrow’s threats.
If you’d like to learn more about how we can help, get in touch today.