A merger or acquisition is one of the most powerful value-creation moments for a business. It’s also one of the most dangerous. When you acquire a company, you don’t just inherit their assets, talent, and technology; you inherit their entire digital history. This includes years of accumulated, often undocumented, digital debt. Systems or processes that leave behind dormant accounts, shadow privileges, misconfigured systems, are quite common.
While leadership focuses on the strategic upside, security teams are left to navigate a chaotic and massively expanded identity attack surface. In this environment, where speed trumps security, threat actors find their greatest opportunities to exploit the chaos.
Why M&A Creates Identity Chaos
- Inheriting a House with Hidden Flaws Acquiring a company is like buying a house without a proper inspection. You see the structure, but you don’t see the faulty wiring or leaky pipes behind the walls. You inherit every misconfigured identity, unmonitored attack path, and legacy authentication flaw.
- Two Sets of Blueprints, No Master Plan The two merging companies may not use the same IAM, IGA, and PAM tools. This creates a fractured governance model with no single source of truth. Security teams are forced to make critical decisions with partial data, trying to manage two separate buildings with two different sets of incompatible blueprints—a dream scenario for an attacker. Often the acquiring companies’ procedures and tools dictate a forward, but this may not always be the best choice.
- Reckless Renovations on a Rushed Timeline M&A integration timelines are notoriously aggressive, driven primarily by business objectives. The pressure to connect systems and grant access for “Day One” operations means standard security workflows are often bypassed. This leads to overly broad permissions, misaligned policies, and a state of constant configuration drift—all in the name of speed.
One need only look at the 2024 ransomware attack on Change Healthcare, a subsidiary of UnitedHealth Group, to understand the stakes. The initial vector was reportedly a server lacking multi-factor authentication—a classic identity-based failure. While the full story is still unfolding, the incident is a textbook illustration of the risks that fester within large, complex, and newly integrated IT environments. When two massive infrastructures are combined, ensuring every single server and identity conforms to the highest security standard is a monumental challenge. A single weak link, inherited during the merger, can lead to a catastrophic system-wide failure.
How Attackers Exploit the M&A Playground
Cyber attackers are opportunists who thrive in chaos. During an M&A, they specifically hunt for:
- Legacy accounts with excessive or forgotten privileges from the acquired company.
- Orphaned service accounts and API keys lingering in now-redundant cloud apps or CI/CD pipelines.
- Misconfigured SSO integrations that create unintended trust relationships between the two environments.
- Delayed deprovisioning of former employees or contractors from the acquired company.
Why Traditional Tools Can’t Manage the Mayhem
Your existing PAM, IAM, and IGA systems were built for a state of relative stability. During an M&A, they fall short because they:
- Assume a single source of truth that simply doesn’t quickly exist for organizations that are merging.
- Don’t perform continuous discovery, meaning new risks created during the frantic integration process go undetected for weeks or months.
- Operate in silos, compounding the complexity and preventing a unified view of risk. Business driving systems may be prioritized for integration, but tese systems may not always be the riskiest or contain the most valuable data for attackers to compromise
Reducing Your Inherited Risk
Phase 1: Pre-Merger Due Diligence – Inspect the Foundation Before the deal closes, identity risk must be a core part of your cybersecurity due diligence. You need a global identity inventory. This means mapping every identity, credential, and entitlement across both organizations before any access is granted.
Phase 2: Integration – Continuously Survey Your New Property Avoid point-in-time snapshots. As you connect systems, you need a real-time, continuous view of new identities, changes in access, and anomalous behaviors. This is precisely where an Identity Attack Surface Management (IASM) platform plays a critical role. It acts as the universal translator and master blueprint, performing continuous discovery of all human and non-human identities, unifying the disparate data, and flagging the hidden risks you’ve inherited.
Phase 3: Post-Integration – Fortify and Remediate
- Correlate All Identities: Map accounts to individuals across every HRIS, directory, and SaaS app to detect duplicates or dangerous overlaps.
- Audit All Privileged Access: Immediately vault every discovered privileged account and key. Enforce credential rotation, least privilege, and Just-in-Time (JIT) access to shrink the attack surface.
- Prioritize with an Attacker’s View: Use an IASM platform to see peer into the acquired companies’ identity landscape, allowing you to prioritize and remediate the most dangerous identity risks prior to integration
Conclusion
An M&A event is not just a financial transaction—it is a massive fusion of identities. While your leadership team rightfully focuses on the growth and strategic advantage, threat actors see it as a once-in-a-lifetime opportunity. By treating identity security as a foundational component of the M&A playbook, you can safely manage what can be a toxic inheritance. An IASM-driven approach ensures that as you build a bigger house, you’re also building stronger walls, finally allowing you to realize the full value of your new assets without inheriting their liabilities.
