Cyber Due Diligence for Private Equity: Assess the Risk Before, During, & After Close

Key Takeaways

• Cyber risk belongs in the deal timeline at three points: before the acquisition, during the transaction, and after close.
• Financial diligence shows what an acquisition target earns. It does not show whether attackers can reach its systems or whether the organization could recover from an attack.
• Threat actors target both sides of a deal, using the uncertainty around a transaction to launch successful phishing attacks.
• A small target is not a low-risk target. Attackers know a private equity-backed owner has the means to pay a ransom.
• Pre-close findings can become a post-close plan that prioritizes remediation and reduces the exposure the acquirer inherits.

Private equity (PE) deal teams read a balance sheet with confidence. However, many have far less visibility into the target’s technology and cybersecurity. That gap matters because once the deal closes, your firm owns every unpatched system, unmonitored alert, and unvetted vendor connection.

Cyber due diligence closes that gap. It identifies cyber risk early enough to price it, plan for it, or walk away from it.

Why Financial Diligence Leaves a Gap

Many deal teams assume IT will integrate easily after close. Many also assume a small target means small risk. Neither assumption holds up.

Attackers see a small organization with a lean IT team as an easier way in. They also know that a PE-backed owner may be more likely to pay a ransom. Consider a target that suffers a ransomware attack before close but waits until the deal has been finalized to encrypt the data. Its systems and data are locked, and the acquirer has paid for assets it cannot use. The buyer then either pays the ransom or absorbs the loss.

Cyber due diligence helps you find the conditions that make this scenario likely before you sign. Our Cyber Risk Services team also supports ransomware readiness and tabletop exercises, which give leadership a chance to rehearse a response before an attack happens.

How We Approach Pre-Close Diligence

Our pre-close IT and cyber assessment for PE buyers starts early in the acquisition process. We start with a short, targeted document request focusing on baseline cybersecurity best practices, then interview technology leadership to confirm what the documents showed and understand how the environment actually runs. We rate the organization against five IT domains and five cyber domains. Each rating reflects the effect on valuation, closing risk, and required investment, so the deal team can price a risk, plan for it, or walk away.

Within those domains, we focus on control design and can also ask for evidence that it works. That includes examining:

• How security is staffed, and whether the team can cover the environment.
• Which monitoring tools are in place, and whether alerts are watched around the clock.
• Whether external vulnerability scans or penetration tests have been performed.
• Whether critical vendors are monitored and provide independent assurance reports, such as SOC 2 reports.
• Whether the incident response playbook has been tested, and whether backup restoration is evidenced rather than only reported.

No single gap would stop a deal. The ratings bring them together so the buyer can see what it is about to inherit, including how to bring the target’s security function into its own.

The Transaction Period Is Also a Target

Risk does not wait for close. Threat actors now target both sides of a transaction with phishing emails. Deals create the kind of uncertainty attackers use. Employees expect unfamiliar messages about new systems, new reporting lines, and payment changes, so a credential-harvesting email looks routine.

Stolen credentials can give an attacker access to the target, buyer, or both. Teams can reduce that exposure by tightening multi-factor authentication, verifying any change to payment instructions by phone, and limiting who can see sensitive material during diligence.

Integration Can Import the Risk

Connecting the target to your environment can expose you to new vulnerabilities. Consider the scope one acquiring organization described to us: move the target’s hardware and users into its own environment, bring accounting onto its ERP system, and set up cash, credit cards, and expense reporting on its platforms. Each of those steps creates a connection point between two environments, and one of them was never vetted.

This is where diligence findings turn into a plan. We organize post-close work by rating. High-risk findings go into the first 100 days. Moderate-risk findings are incorporated into the first-year plan and budget. Low-risk findings require no action beyond routine monitoring. Two items belong at the top of almost any plan:

1. Third-party risk. Evaluate the target’s vendors immediately. Without diligence and monitoring, you cannot see how much risk those connections carry.
2. External exposure. We can run a non-intrusive scan of the target’s external-facing assets to show the vulnerabilities an outside attacker could see.

The scan looks at what an outside attacker can see without touching the target’s systems: internet-facing domains and IP addresses, open ports, outdated software, expired certificates, and misconfigured cloud services. We pair it with threat intelligence, which shows whether the target’s infrastructure appears in known attacker activity, and a dark web search for leaked employee credentials, stolen data, or chatter that names the organization.

Because these sources are public or third-party, the work can run early in the deal, before the buyer has any access to the target’s network. The buyer receives a prioritized summary of exposed assets, vulnerabilities, and credential leaks, rated by severity, that feeds directly into the risk ratings and the first-100-days plan. A leaked password or an unpatched remote access point can also be a sign the target has already been compromised, which is worth knowing before you sign.

What to Do Before Your Next Deal

• Add cyber and IT diligence to the deal timeline early, alongside financial diligence.
• Ask for evidence, not assurances: testing results, monitoring coverage, and vendor reports.
• Plan for heightened phishing risk from the day the deal becomes known.
• Evaluate third parties as soon as the deal closes, and sooner if the timeline allows.
• Build the integration plan before close, so remediation has an owner, a budget, and a schedule.

Cyber risk can be identified, and a remediation plan can reduce what you inherit. To discuss cyber due diligence for your next transaction, contact our Cyber Risk Services team using the form.