For many organizations, legacy systems are still the backbone of critical business operations. They run billing, logistics, manufacturing systems, financial systems, payroll in many cases and even customer records. When faced with a cyberattack, software defect, or natural disaster, the consequences are immediate for businesses and downstream partners.

Over the last five years alone, there have been several high-profile incidents showing how quickly a technology failure can become a business crisis. The lesson is simple: legacy systems don’t fail gracefully; and if you don’t have a plan, recovery becomes exponentially harder and more expensive. With so much socio-economic turmoil across the planet right now, having concerns about ‘how’ you will handle a legacy system failure should not be an added stressor.

This week we became aware of the immediate impacts of a flood. The ‘disaster’ while not a software problem, was the result of a legacy system failure. The rapid and coordinated response immediately enacted by the incident response team got us thinking that it was time for a blog about what business leaders need to know when disaster strikes their legacy systems.

When Systems Go Down, Business Stops

Simply put, the operational impact of a system outage is often underestimated until it happens.

Take the 2021 ransomware attack on Colonial Pipeline, one of the largest fuel pipeline operators in the United States. The attack forced the company to shut down its entire pipeline network, which is responsible for transporting roughly 45% of the fuel supply on the U.S. East Coast. This attack on their billing systemled to widespread fuel shortages and price spikes. The company ultimately paid about $4.4 million in ransom to obtain a decryption tool to restore operations. The restoration and outages lasted eight (8) days but impacted millions of people including: end user consumers, businesses, branches of government, and transportation and logistics networks.

Similarly, the 2024 ransomware attack on CDK Global, a software platform used by thousands of car dealerships across North America, brought dealership operations to a halt. The outage disrupted sales, financing, and inventory systems across the U.S. and Canada, and the company reportedly paid $25 million to attackers as part of the recovery effort.

Even municipal systems have been impacted. In the 2019 Baltimore ransomware attack, city services including payment systems and public databases were offline for months. The estimated damage to the city was $18 million, and the IT Director was put on leave absence for his mishandling of the outage and lack of a written disaster recovery plan.

These incidents highlight a critical truth: system outages quickly escalate into financial, operational, and reputational crises.

First Steps When Disaster Happens

When a legacy system goes down, especially due to a cyber incident, time matters. Leadership teams should focus on three priorities immediately.

1. Contain the issue.
Isolate affected systems to prevent further spread of malware or corruption. This may mean disconnecting servers, halting integrations, or disabling remote access.

2. Activate your incident response team.
This includes internal IT (or external partner if you outsource this), technical security teams, legal counsel, communications teams, and any external cybersecurity or software partners.

3. Shift to manual or contingency operations where possible.
In the Atlanta government ransomware attack, employees had to revert to paper forms for basic operations after systems were taken offline. While inefficient, it allowed essential services to continue.

These first steps are critical to stabilizing operations while recovery efforts begin.

If, after reading this list, you identify a gap in your own organization’s incident response plan, now is the time to pivot to plan creation. We wrote a blog back in 2020, 10 Tips for Developing a Disaster Recovery Plan (DRP) to help you get started.

The Importance of Planning

The difference between a manageable incident and a business catastrophe often comes down to one thing: a well-tested disaster recovery plan (DRP).

Effective DRP strategies typically include:

• Regular system backups, stored securely and offline
• Defined recovery time objectives (RTO) and recovery point objectives (RPO)
• Documented system architecture and dependencies
• Clear incident response procedures

Unfortunately, many organizations running legacy platforms lack these basics. In older environments, documentation is often the first point of failure; it may be incomplete, lost, or never created in the first place.

When that happens, recovery becomes a forensic exercise; teams must first figure out how the system works before they can fix it. This exercise often falls on the ‘hero team member’ and their memory, if they are still on staff. When they are not, outside triage expertise becomes critical.

The Value of Trusted Third-Party Triage Experts

Third-party specialists can often step in, triage the system failure and fill that knowledge gap when the original engineers who built the system are not available.

Legacy experts typically bring:

• Deep experience working with aging platforms and legacy languages
• Reverse-engineering capabilities for undocumented systems
• Proven disaster recovery frameworks
• Incident response expertise for cyber events

Large-scale incidents like the Kaseya VSA ransomware attack, bring to light the importance of third-party support. This case affected more than 1,500 companies and their downstream partners by exploiting a zero-day vulnerability in their Virtual System Administrator software. Many of these organizations relied heavily on external cybersecurity and recovery experts to restore systems and investigate the breach.

In many cases, the cost of emergency external expertise is negligible compared to the cost of prolonged disruption.

What If You Have No Documentation?

This is a surprisingly common scenario with legacy environments.

If documentation doesn’t exist, recovery efforts should focus on reconstructing knowledge quickly:

1. Identify system dependencies.
Map out integrations with databases, APIs, infrastructure, and third-party services.

2. Capture institutional knowledge.
Interview long-tenured staff, vendors, and former contractors who may understand parts of the system.

3. Perform code analysis.
Experienced legacy engineers can analyze the codebase to identify critical functions and architecture patterns.

4. Document everything moving forward.
Even partial documentation dramatically improves future recovery efforts.

The goal isn’t perfection, it’s building enough understanding to stabilize and rebuild operations. If documentation does not exist and you are not facing an immediate disaster, starting with a Code and Infrastructure Audit is one of the most cost effective methods to establish a baseline for ‘stabilization documentation.’

The Cost of Doing Nothing

Many organizations delay investing in resilience because legacy systems appear stable. But stability can be misleading.

When these systems fail, the costs extend far beyond IT repair:

• Lost revenue and halted operations
• Regulatory and compliance exposure/fines
• Legal liability
• Customer churn and brand damage
• Long-term recovery costs

As recent cyber incidents demonstrate, the ripple effects can extend far beyond the organization itself, impacting supply chains, customers, and even national infrastructure.

The Bottom Line

Legacy systems aren’t going away anytime soon. For many businesses, they will remain mission critical for the foreseeable future.

But, relying on them without a clear recovery strategy is a risk few organizations can afford.

Business leaders should ensure their organizations have:

• Tested disaster recovery plans
• Documented system architecture
• Strong vendor and third-party support relationships
• Access to triage experts who can respond quickly when things go wrong

Because when disaster strikes, the question won’t be whether your systems fail,

it will be how quickly you can recover.

If you need help with anything we discussed in this week’s blog, reach out, we offer complimentary 30-minute consultations to help you determine what’s next.