For years, enterprise security focused on building the “perfect defence” – layering firewalls, endpoint tools, and perimeter controls to keep attackers out. That approach no longer works.
“Assume we’re compromised. Assume the attackers are already in the network, exfiltrating data, and waiting for the big bang – ransomware, data wipe, disruption.” – Haydn Wall, Head of Managed Security Services
Cloud adoption, distributed workforces, and AI-driven social engineering have dissolved the traditional perimeter. Attackers can sit undetected in an environment for weeks or months, quietly gathering data before striking. The reality for security leaders is simple: it’s not if an attacker gets in – it’s how fast you can detect, contain, and recover.
Shifting the Mindset
This requires a fundamental change in perspective, moving away from the idea of preventing every breach, and instead building resilience on the assumption that compromise is inevitable. This “assume breach” mindset is not pessimistic – it’s pragmatic. It requires leaders to operate as though compromise is already happening, and to build systems, teams, and processes that can:
- Detect malicious activity quickly and accurately
- Contain and remediate before damage escalates
- Learn and adapt from every incident or simulation
Four Practical Steps for Security Leaders
So how do you put this mindset into practice? It starts with embedding proactive measures into day-to-day operations.
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Maintain live, tested incident response playbooks
Incident response plans must be more than static documents. Playbooks should be current, role-specific, and rehearsed regularly across the organisation. A PDF buried on the intranet won’t help when ransomware hits at 2 am. Teams must know the exact steps to take – and rehearse them.
“The key thing is always running regular simulations and exercises. Playbooks can’t just be written and forgotten; they have to be practised and kept up to date, so when an incident happens, the containment steps are second nature.” – Haydn Wall
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Run continuous breach simulations
Breach and Attack Simulations (BAS) allow you to test your defences against real-world tactics. Choose scenarios that mirror current threats – for example, variants targeting your industry – and run them regularly. The goal is not only to test technology, but to confirm that monitoring, escalation, and containment processes work under real pressure.
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Close the gap between detection and action
Speed matters – but without precision, it’s noise. More alerts don’t mean better protection. If your MDR programme is flooding your team with low-value threats, it’s not helping – it’s hindering. The best programmes cut through the noise, surface what matters, and enable fast, confident action.
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Address the human factor
“The biggest issue is still the end user – they have always been the weakest link. Products alone won’t save you; the mindset has to shift across the business.” – Haydn Wall
Every employee plays a role in resilience – from frontline staff to boardroom leaders. By fostering a culture of conscious security awareness, we move beyond tick-box training to real behavioural change.
Why Speed and Accuracy Define Resilience
Even with robust playbooks, simulations, and awareness programmes in place, the defining factor in resilience is how effectively threats are detected and contained in real time.
Once a breach occurs, dwell time becomes the defining metric. Every hour undetected gives attackers more opportunity to escalate. Accuracy ensures the right incidents are addressed immediately, avoiding wasted effort on false positives.
But more detection doesn’t always mean better protection. If a security team is overwhelmed by volume, they risk missing the most critical threats. It’s not just about catching everything – it’s about catching what matters. And that requires precision.
Regular simulations make both possible. By testing against emerging threats and feeding the findings into detection rules and processes, organisations build the agility to respond decisively when real incidents occur.
Where to Start
Adopting an “assume breach” mindset is not a one-off project – it’s an ongoing discipline.
Security leaders should:
- Schedule breach simulations as a recurring part of operational planning
- Embed IR playbook testing into quarterly exercises
- Make detection tuning and threat intel integration part of routine operational activities
- Treat user awareness as a core layer of defence, not a side project
Turning Readiness into Advantage
Perfect defence is a myth. Resilience – the ability to contain, recover, and adapt faster than the threat – is the true differentiator.
At Gamma, we work with enterprises to implement continuous simulation, refine detection accuracy, and ensure incident response plans are ready to deploy at speed. Our MDR and BAS capabilities combine around-the-clock monitoring, expert-led response, and real-world attack simulation to keep resilience high and dwell time low.
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