Mergers & Acquisitions Cybersecurity Due Diligence

Know exactly what you're acquiring, before you sign.

Every M&A transaction carries cybersecurity risk. Undisclosed breaches, inherited vulnerabilities, legacy infrastructure, and overstated security posture are among the most common, and most expensive surprises a buyer can face post-acquisition. Our CREST-accredited consultants provide independent, expert-led cybersecurity due diligence that gives your deal team a clear, accurate picture of the target’s security posture before the transaction completes.

Cybersecurity In M&A

Why Cybersecurity Due Diligence Matters

The security posture of an acquisition target can have a direct and material impact on deal value. Vulnerabilities in acquired systems become your vulnerabilities the moment the transaction closes. Undisclosed breaches trigger regulatory notification obligations. Legacy infrastructure carries remediation costs that weren’t in the financial model. And in regulated industries, inheriting non-compliant systems can create immediate compliance exposure.

Cybersecurity due diligence is no longer optional, it is a standard component of responsible M&A practice. The question is whether you conduct it before the transaction, when findings can inform valuation and deal terms, or discover the issues afterwards, when the leverage is gone.

Pentest Limited - Mergers and Acquisitions

Our M&A Clients

Who We Work With

Our M&A cybersecurity due diligence service is designed for:

Acquirers & Deal Teams

Those looking to understand the true security posture of a target before finalising deal terms or valuation.

Private Equity Firms

We can help you assess portfolio companies prior to acquisition, recapitalisation, or exit.

Sell-Side Organisations

Demonstrate credibility, validate security posture, and remove cybersecurity as a deal risk for potential buyers.

Legal & Financial Advisors

Those requiring independent technical assessment as part of broader due diligence workstreams.

M&A Test Coverage

What Our M&A Cybersecurity Due Diligence Covers

Every M&A engagement is scoped to the transaction, the target’s environment, the deal timeline, and what your team needs to know to make an informed decision. We work with your deal team to agree scope quickly and deliver findings within your transaction window.

Network Reconnaissance & Asset Discovery

One of the most common M&A surprises is shadow IT, infrastructure that exists but isn't documented, disclosed, or managed. Network reconnaissance provides a real-time picture of what's actually on its network, uncovering the true attack surface.

> Full network asset discovery and enumeration
> Identification of undisclosed or shadow IT infrastructure
> Internet-facing asset mapping and exposure assessment
> Comparison of discovered assets against disclosed scope

External & Internal Infrastructure

A thorough assessment of the target's network infrastructure, both the external perimeter and internal environment, identifying vulnerabilities, misconfigurations, and security gaps that would become your responsibility post-acquisition.

> External perimeter testing and exploitation of internet-facing services
> Internal network assessment covering servers, devices, and services
> Active Directory configuration and privilege escalation assessment
> Patch management posture and end-of-life system identification

Web & Mobile Applications

If the acquisition includes software products, customer-facing applications, or internal tools, manual application testing identifies vulnerabilities that could represent regulatory risk, reputational exposure, or post-acquisition remediation cost.

> Manual web and mobile application testing aligned to OWASP
> Authentication, access control, and session management assessment
> Injection vulnerabilities and business logic flaw identification
> API security assessment for application back-end services

Cloud Environment Assessment

For targets with cloud infrastructure in scope, we assess the security configuration of their AWS, Azure, GCP, or Oracle Cloud environment, identifying misconfigurations, overpermissioned identities, and exposed resources that represent inherited risk.

> IAM configuration and privilege escalation path assessment
> Storage bucket and blob exposure identification
> Network security group and firewall rule review
> Logging, monitoring, and detection control assessment

Red Team Simulation

Where a deeper assessment is required, particularly for high-value acquisitions or targets in sensitive industries, a red team engagement simulates a real-world threat actor attempting to access the organisation's most critical assets. This goes beyond technical vulnerability identification to assess the target's detection and response capability, providing the most comprehensive picture of their security posture available.

> Simulated attack across all vectors - technical, physical, and social
> Assessment of detection and response capability
> Identification of paths to critical assets and sensitive data
> Findings presented in terms of real-world business impact

Our Test Process

Our M&A Due Diligence Process

Every M&A test goes through a rigorous process to ensure you get the best possible results. Below we outline the key stages our testing goes through:.

Scoping & Timeline Agreement

We work with your deal team to agree the scope, depth, and timeline of the assessment, ensuring our engagement fits your transaction window and delivers the findings you need to make an informed decision.

Manual, Expert-Led Testing

Your assessment is carried out by directly employed, CREST-certified consultants. Every finding is the result of manual investigation, not automated scanner output. That means validated vulnerabilities, accurate risk assessment, and findings that stand up to scrutiny.

Reporting Tailored To Your Needs

Our reports are written for deal teams and boards, not just technical audiences. Findings are presented in terms of business impact and deal risk, with executive summaries, risk registers, and remediation cost guidance designed to feed into your transaction process.

Post-Test Delivery Support

We remain available after delivery to answer questions from your deal team, legal advisors, or the target's technical team, and to provide additional documentation or clarification as required during the transaction process.

Contact Us

Discuss Your M&A Cybersecurity Requirements

Working to a deal timeline? Fill in the form below and a member of our team will be in touch to discuss your requirements and agree a scope.