How to reduce your organization’s exposure to third-party cyber-breaches

As digital ecosystems expand and organisations rely on increasingly complex networks of external providers, third-party cyber-incidents are fast becoming the norm rather than the exception. In 2025, nearly 30 per cent of reported global data breaches were linked to third-party vendors, double the proportion seen the year before. 

 

What is a third-party cyber-breach? 

 

A third-party cyber-breach occurs when a company is compromised through one of its external vendors, partners, contractors or service providers, rather than through a direct attack on its own systems.  

 

These third parties often include: 

• Cloud and SaaS platform providers 
• IT service providers and managed service providers (MSPs) 
• Payroll, HR and other operational vendors 
• Customer service, marketing, and analytics platforms

A breach through a third party is particularly attractive for bad actors because it can be just as damaging for organisations, or even worse, because: 

• Vendors often hold privileged system access 
• Organisations typically have limited visibility into vendor security environments 
• Breaches may go undetected for extended periods 
• A single compromised vendor can impact hundreds or even thousands of downstream customers 

Why third-party cyber-breaches keep rising 

 

The growth in third-party cyber-incidents is not coincidental. It reflects how modern organisations operate today. Several structural factors are driving this trend. 

1. Organisations are more dependent on vendors than ever 

 

Every business function now relies on external platforms, from finance and HR to customer service, sales and supply chain operations. While SaaS adoption has delivered enormous efficiency gains, it has also significantly expanded the attack surface beyond internal IT environments. 

2. Vendors often have excessive or persistent access 

 

To operate effectively, vendors frequently require access to internal systems, data or credentials. Once attackers compromise a vendor, they can often move laterally into client environments with little resistance – sometimes without triggering immediate alerts. Several high-profile breaches in 2025 followed this exact pattern. 

 

3. Vendors are prime targets for social engineering 

 

Attackers increasingly recognise that breaching a vendor employee is often easier than penetrating the defences of a large enterprise. A single successful compromise can provide access to multiple organisations, offering a high return on investment for threat actors. 

 

4. Internal teams aren’t sharing risk-critical information 

 

Third-party cyber-risk is often treated as an IT issue, yet many of the most important controls sit with compliance, legal, procurement and risk teams. These groups manage contracts, due diligence, SLAs, data-handling obligations and monitoring requirements. 

 

When this information is fragmented across teams, no one has a complete view of vendor risk. During an incident, this lack of shared visibility can delay detection and response – allowing breaches to escalate unnoticed. 

 

5. Lack of continuous monitoring  

 

Many organisations conduct vendor risk assessments only during onboarding. But vendors don’t remain static over time. They may change systems or infrastructure, introduce new subcontractors or update software or security controls. Without continuous monitoring, early warning signs are easily missed. 

 

What you can do about it 

 

While third-party cyber-breaches are increasing, they are not inevitable. Organisations can take practical steps to reduce exposure and improve resilience. 

 

Strengthen vendor contracts and security requirements 

 

Cyber-security expectations should be embedded into vendor agreements from the outset. Contracts should require suppliers to meet defined security standards, report incidents promptly, undergo audits, follow strict data-protection practices and maintain appropriate cyber-insurance. 

Security must be treated as a core component of the commercial relationship, not as an afterthought. 

 

Educate teams on vendor-based threats 

 

Employees interact with vendors daily, making them frequent targets for social engineering. Regular training should help staff recognise vendor impersonation attempts, spoofed SaaS login pages, fraudulent support requests and fake invoices or contract amendments. Awareness remains one of the most effective controls. 

Implement continuous vendor risk monitoring 

 

Annual questionnaires alone are no longer sufficient. Organisations need ongoing visibility into vendor security posture, vulnerabilities, infrastructure changes and emerging risks. 

Continuous monitoring enables earlier detection, faster response and more informed decision-making across the vendor lifecycle. 

 

Summary 

 

Third-party cyber-breaches aren’t rising by accident. They are the result of expanding vendor ecosystems, accelerated SaaS adoption and attackers who increasingly view suppliers as the most efficient route into enterprise environments. 

 

As organisations move further into 2026, the key question is no longer whether a vendor will be breached but how quickly you can detect, contain and mitigate the impact when it happens. 

---

To explore more such resources and practical guidance on managing third-party risk, visit www.ethixbase360.com

---

By Natasha Martin, Global Head of Product & Proposition, Ethixbase360