Testing Resilience Beyond the Perimeter

Service Overview

Perimeter defences are not infallible. Sophisticated adversaries consistently bypass external protections, whether through supply chain attacks, phishing campaigns, or zero-day exploits. The question is not if an attacker will gain initial access, but how far they can go once inside.

SilentGrid’s Assumed Breach Assessment starts from the premise that your perimeter has already been compromised. This controlled exercise simulates post-breach scenarios to evaluate your organisation’s ability to detect, respond to, and contain adversarial movement within the internal network.

By replicating the tactics, techniques, and procedures (TTPs) of advanced threat actors, SilentGrid tests your organisation’s ability to mitigate lateral movement, privilege escalation, and data exfiltration – exposing blind spots and operational gaps that often go unnoticed until a real incident occurs.

Why Assumed Breach Assessments Are Critical

Beyond External Threats – The Reality of Modern Attacks

Modern adversaries do not stop at breaching the perimeter. Once inside, attackers exploit misconfigurations, unpatched systems, and overlooked vulnerabilities to achieve persistence, access sensitive data, or escalate privileges.

Assumed Breach exercises reveal:

• How easily attackers can navigate internal systems.
• Gaps in segmentation, access controls, and detection capabilities.
• The effectiveness of SOC, IR, and monitoring solutions under real-world conditions.

SilentGrid’s Approach

SilentGrid’s Assumed Breach assessments are built on years of offensive security experience and a deep understanding of adversary behaviours. We simulate realistic attack paths using custom tooling, stealth techniques, and insider threat emulation to provide actionable insights into your internal defences.

Our Methodology

1. Establishing Initial Foothold

   • Simulate scenarios such as:
     • Compromised endpoints or user credentials
     • Malware deployment through spear phishing
     • Insider threat emulation from compromised accounts or rogue employees
   • Evaluate your endpoint detection and response (EDR) capabilities in recognising malicious footholds.

2. Privilege Escalation and Lateral Movement

   • Exploit misconfigurations, weak passwords, and insecure protocols to escalate privileges.
   • Move laterally across networks using legitimate administrative tools to avoid detection.
   • Test the efficacy of Active Directory controls, segmentation, and access restrictions.

3. Target Discovery and Data Exfiltration

   • Identify sensitive systems, databases, and internal applications to access critical data.
   • Simulate data exfiltration through bypass techniques, evaluating Data Loss Prevention (DLP) and monitoring systems.

4. Incident Response Evaluation

   • Test how quickly your teams:
     • Detect and respond to internal breaches.
     • Escalate and contain adversary movement.
     • Adjust monitoring, alerting, and log analysis pipelines.
   • Highlight gaps in SIEM visibility, SOC workflows, and playbook execution.

Deliverables and Reporting

SilentGrid provides comprehensive, actionable intelligence to improve your internal security posture.

You will receive:

• Detailed Attack Chain Report – A full breakdown of tactics used during the engagement, mapped to the MITRE ATT&CK framework.
• Privilege Escalation Paths – Documentation of exploitable misconfigurations and vulnerabilities, prioritised by risk.
• Data Access and Exfiltration Report – Demonstrating how sensitive data could be accessed and exfiltrated undetected.
• Incident Response Analysis – A review of response times, detection points, and containment efficiency.
• Executive Summary – High-level insights for leadership, outlining key weaknesses and strategic recommendations.

Key Benefits of Assumed Breach Assessments

• Test Internal Defences Under Realistic Conditions
  Measure the resilience of internal networks, user permissions, and EDR configurations against real-world adversaries.

• Strengthen Incident Response Readiness
  Evaluate how well your SOC, IR teams, and detection mechanisms respond to post-compromise activity.

• Identify Lateral Movement Risks
  Detect misconfigurations, trust relationships, and vulnerabilities that facilitate unrestricted movement within the environment.

• Actionable Security Uplift
  Receive prioritised recommendations to harden internal segmentation, user policies, and access controls.

• Prepare for Targeted Ransomware
  Assumed Breach simulations reflect the early stages of ransomware activity, helping to mitigate real-world risks.

Beyond the Test – Continuous Security Improvement

An Assumed Breach exercise is not a one-off event. SilentGrid partners with organisations to offer iterative testing, follow-up engagements, and remediation validation.

• Re-test Vulnerabilities and Attack Paths after remediation.
• Simulate New TTPs based on evolving adversary trends.
• Validate Detections by replicating attack chains in a controlled environment.

Is Assumed Breach Right for Your Organisation?

Assumed Breach assessments are ideal for organisations that:

• Operate mature external defences but need to evaluate internal resilience.
• Want to simulate insider threats or persistent attackers operating within their environments.
• Require validation of EDR, segmentation, and incident response procedures.
• Need to demonstrate resilience to stakeholders and executive leadership.

Get Started with Assumed Breach Testing

SilentGrid’s Assumed Breach service exposes hidden risks and empowers your teams to detect and contain internal threats.
Contact Us to schedule an engagement and assess your organisation’s resilience against internal adversaries.