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Assumed Breach Penetration Testing
Assess your organisation’s ability to detect, respond to, and contain a breach
Our assumed breach penetration testing evaluates how effectively your organisation detects, responds to, and contains attacks after initial compromise, helping protect critical systems and sensitive data.
What is assumed breach penetration testing?
Assumed breach penetration testing is a specialised form of penetration testing that evaluates security from a post compromise perspective. Rather than attempting to breach external defences, assumed breach testing begins with initial access already established, reflecting how many modern cyber attacks unfold in reality.
This assumed breach approach may simulate scenarios such as compromised credentials, physical access, successful social engineering, or physical intrusion. From there, testers assess how attackers could move through the internal network, exploit active directory, escalate privileges, and access critical assets.
Unlike penetration testing focused purely on prevention, breach testing assesses detection, containment, and response, providing a realistic view of how your organisation handles malicious activity.
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Why choose Zensec
We combine deep technical expertise with practical, real-world experience to deliver CREST-accredited penetration testing services that truly make a difference. Our cyber security experts don’t just run scans, they identify and exploit vulnerabilities the way real attackers would, helping you uncover security flaws before they become security incidents. We tailor every engagement to your specific business operations, including cloud platforms, computer systems, and critical assets, ensuring complete alignment with your threat landscape.
Our transparent scoping process means you get clear insight into your pen test cost before anything begins. We provide detailed reports with actionable remediation advice, and support you beyond the test with strategic guidance. Whether you’re pursuing compliance with frameworks like Cyber Essentials or defending against the latest emerging threats, we deliver results that strengthen your security posture. Zensec ensures your investment delivers not just visibility, but lasting protection, through rigorous testing, expert support, and a commitment to ongoing improvement with regular penetration tests on a continuous basis.
We are equipped to deal with an attack from any ransomware group.
Don’t hesitate to contact us if you are under attack from a ransomware group not listed above.
The importance of assumed breach penetration testing
Many organisations invest heavily in perimeter defences, yet real attackers frequently bypass them through phishing, credential theft, or insider compromise. Once inside, weak network segmentation, inadequate monitoring, and limited response processes can allow attackers to operate undetected.
An assumed breach exercise helps organisations identify gaps that may not be uncovered through external penetration testing or other traditional penetration tests. These include weaknesses in internal visibility, delayed response, and insufficient controls around sensitive information and critical systems.
Proactive assumed breach assessments help you:
Identify weaknesses in internal security and response processes
Assess the effectiveness of incident response plans
Understand attacker attack paths and attack vectors
Evaluate how quickly malicious activity is detected and contained
Protect sensitive data and business critical systems
Improve resilience against realistic threats
Key features
We follow a structured, realistic approach that mirrors how attackers behave after a breach, while ensuring testing remains safe and controlled.
Pre engagement scoping
We define the scope, objectives, and specific scenarios to be tested. This ensures good coverage of critical assets, business processes, and security controls.
Initial access simulation
We simulate initial access through agreed entry points, such as compromised credentials, internal footholds, or limited physical access. This reflects real world breach conditions without testing perimeter defences.
Post breach exploitation
Our testers attempt to move laterally, escalate privileges, obtain local admin rights, deploy web shells, or exploit misconfigurations in active directory, web applications, cloud services, and internal systems.
Detection and response assessment
We assess your organisation’s response capabilities, including alerting, monitoring, and incident response actions. This phase evaluates how effectively threats are detected, investigated, and contained.
Reporting and recommendations
All findings are documented in a detailed report, outlining vulnerabilities discovered, attacker techniques used, and the overall effectiveness of security controls. We provide clear, actionable recommendations to improve detection, response, and containment.
Zensec’s consultants bring deep experience delivering assumed breach exercises, red team engagements, and advanced breach assessments. Our focus is not just on exploitation, but on helping organisations understand how well their people, processes, and technology respond under pressure.
An assumed breach penetration test provides one of the most effective ways to understand how your organisation would perform during a real incident. It delivers clarity on response effectiveness, control gaps, and areas requiring immediate improvement.
Contact Zensec today to schedule an assumed breach assessment and strengthen your organisation’s ability to detect, respond to, and recover from modern cyber attacks.
Explore Our Penetration Testing Services
Comprehensive offensive security assessments tailored to your organisation’s threat landscape.
Uncover vulnerabilities in your web apps before attackers do.
Secure your iOS and Android applications against real-world threats.
Test your perimeter defences from an outsider’s perspective.
Identify risks an insider or compromised device could exploit.
Full-scope adversary simulation to stress-test your entire security posture
Simulate a compromised network to measure detection and response.
Collaborative red and blue team exercises to sharpen your defences.
Evaluate your people’s resilience against phishing and manipulation.
Discover what attackers can learn about you from public sources.
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Frequently asked questions
Key information when you’re under pressure.
Assumed breach penetration testing differs from traditional penetration tests by starting from the position that a breach has already occurred. Unlike standard penetration testing, which focuses on preventing access, an assumed breach assessment evaluates what happens after an attacker has gained initial access. This approach provides deeper insight into internal security, response effectiveness, and how well an organisation can contain malicious activity once perimeter defences are bypassed.
Assumed breach testing can be tailored to specific threat scenarios relevant to your organisation. This may include compromised credentials, social engineering, physical access, physical intrusion, or an attacker already present within the internal network. These assumed breach exercises allow organisations to assess how attackers exploit attack vectors, move through systems, and compromise critical assets under realistic conditions.
Yes. Assumed breach penetration testing often overlaps with red team engagements and red team exercises, but with a more focused scope. While a full red team may test detection across the entire organisation, assumed breach testing concentrates on post compromise behaviour such as escalating privileges, gaining local admin rights, deploying a web shell, or attempting to deploy ransomware to evaluate detection and response capabilities.
At the end of an assumed breach assessment, you will receive a detailed report outlining vulnerabilities discovered, attacker attack paths, control failures, and areas where detection or response was delayed. The report includes actionable recommendations to improve incident response, strengthen security measures, and reduce the risk of future compromise. This helps organisations assess the overall effectiveness of their controls and improve their ability to respond to realistic threats.
Dealing with a ransomware attack?
Our ransomware recovery service can help
Our expert team works quickly to contain the breach, recover your data, and restore your systems to full operation. We’ll guide you through every step of the recovery process and help strengthen your defences to prevent future attacks. Regain control with Zensec - trusted support when it matters most.