Breach and Attack Simulation: A Complete Guide

Technical Reviewers
Updated: February 4th, 2025
10 mins read
A guide to breach and attack simulation.

Today, cybersecurity isn’t just about protecting data but about protecting operations, reputation, and trust. Unfortunately, many organizations continue to operate under the false assumption that their security posture is strong because they’ve checked off compliance boxes—only to be blindsided when a breach occurs.

Moreover, security teams are often so focused on responding to what has already happened or what’s mandated by regulations that they overlook the most critical aspect of cyber defense—anticipation. 

This is where Breach and Attack Simulation (BAS) shifts the conversation. By continuously simulating various sophisticated attack scenarios, it systematically and constantly tests and improves defenses to ensure they’re ready for tomorrow’s threats, not just today’s.

What is Breach and Attack Simulation and Why Now?

Breach and Attack Simulation (BAS) is a proactive, real-time adversarial testing framework that continuously emulates attacker behaviors across an organization’s digital landscape. It provides an ongoing, dynamic security posture assessment by simulating advanced persistent threats (APTs), insider threats, and emerging attack vectors in a controlled environment.

Unlike traditional pentests, BAS doesn’t just test vulnerabilities—it actively measures the efficacy of existing security controls, response mechanisms, and detection capabilities against evolving threats to assess whether security investments work in the face of modern attack strategies.

How BAS Security Works: The Process

breach and attack simulation security process

Step 1: Simulating Real Attacks 

Execute controlled attack scenarios across endpoints, networks, cloud environments, and identities that go beyond simple vulnerability scans, replicating adversaries’ full-chain attack techniques.

Step 2: Validating Security Controls  

Instead of mapping exposures, this step actively tests whether security defenses such as SIEMs, EDRs, and firewalls detect, block, or respond effectively. It continuously surfaces misconfigurations, alerting gaps, and response failures.

Step 3: Measuring Lateral Movement and Impact 

Unlike traditional security testing, which often stops at initial access, this step assesses how an attacker could pivot across systems, escalate privileges, and exfiltrate data to offer a clearer picture of potential business impact.

Step 4: Adapting and Iterating 

Attack scenarios don’t remain static. As new threats emerge, simulations evolve, security gaps are re-tested, and response strategies are fine-tuned, turning security from a reactive function into an ongoing, adaptive process.

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Why Now?

1. Breaking the Fortress Mentality: Assumptions vs. Reality

For years, cybersecurity strategies have operated under a flawed assumption: build stronger walls, and attackers will struggle to break in. This fortress mentality has shaped security investments, leading to complex, layered defenses. But today’s threat landscape has proven that walls don’t always work—attackers don’t always break in; sometimes, they walk through the front door via compromised credentials, supply chain attacks, or zero-day exploits.

Example: In 2023, MGM Resorts suffered a major breach when attackers used social engineering to bypass multi-factor authentication, gaining access to critical systems without breaking traditional defenses. Despite strong perimeter controls, a simple phone call exploiting human error led to more than $100 million in losses

BAS simulation forces security teams to shift from a passive, checklist-driven approach to one that actively tests assumptions, exposing where defenses work and—more importantly—where they fail. Simply put, a BAS simulation reinforces compliance bases and frameworks by pinpointing gaps by testing real-world attack paths beyond network defenses.

2. Shifting to a Continuous Security Model: Adapt or Be Breached

Security testing has historically been event-driven—pentests before audits, red teaming for compliance, and tabletop exercises for crisis preparation. The problem? Attackers don’t wait for scheduled tests. When a new vulnerability emerges, defenses must be reassessed, and relying on annual or quarterly security reviews leaves organizations perpetually exposed.

Example: In 2024, attackers exploited stolen passwords to breach Snowflake accounts, impacting multiple companies, including giants like Ticketmaster and AT&T, compromising nearly 60 million customer data. Relying on periodic assessments, the breach went undetected for weeks—far exceeding the industry average Mean Time to Detect (MTTD) of 16 days. 

BAS shifts security from reactive testing cycles to continuous validation, creating a feedback loop where teams aren’t just discovering a laundry list of critical threats every few months but learning how to adapt and respond proactively. It turns security into an iterative, self-improving process where detection and response mechanisms evolve as fast as the threats they face.

CriteriaBASCTEMPentesting
DefinitionAutomated simulation of real-world attacks to test the real-time effectiveness of security controls and detection mechanisms.Continuous assessment of an organization’s exposure to external and internal threats, monitoring and mitigating risks through automated threat intelligence.Manual or automated assessment where testers exploit vulnerabilities to assess potential attack paths and the effectiveness of security defenses.
Scope of TestingCovers a wide range of attack vectors (network, endpoint, cloud, email, etc.) and adversarial tactics, techniques, and procedures (TTPs) aligned with frameworks like MITRE ATTACK.Focuses on continuous exposure to threats, tracking and managing risks across multiple attack surfaces (vulnerabilities, misconfigurations, etc.) and helping prioritize mitigation.Primarily focused on identifying vulnerabilities in systems, applications, and networks, often using a pre-defined set of attack scenarios.
Frequency of TestingContinuous, real-time validation of security controls and detection systems. Testing is automated and ongoing.Continuous and dynamic, with constant threat monitoring and risk management across the organization's environment.Typically periodic, such as quarterly or annually, with a fixed start and end point for each engagement.
MethodologySimulates real-time attacks to test security defenses' resilience without exploiting actual vulnerabilities to validate detection and response effectiveness.Uses threat intelligence feeds and real-time data analysis to continuously monitor and assess threat exposure with automated scanning, risk prioritization, and alerting.Manual or automated attacks are carried out to exploit identified vulnerabilities and gain unauthorized access. Typically involves a combination of black-box, white-box, or grey-box testing methods.
Depth of EngagementFocuses on testing how well security systems handle real-time attacks, assessing vulnerabilities, detection, and response capabilities.Focuses on overall exposure and risk mitigation, using automated tools to provide ongoing visibility into external and internal threats.Focuses on exploitation and identifying specific vulnerabilities to uncover weaknesses but doesn’t always assess full system resilience.
Target AudienceSecurity operations teams, SOC analysts, and incident response teams need continuous validation of security controls.Security leaders and risk managers who require continuous monitoring and insights into an organization’s threat landscape.Security teams and organizations are looking to individually evaluate the security of specific systems, applications, or networks.
AutomationFully automated, with predefined attack scenarios and real-time simulations. Results are continuously updated to reflect emerging threats.Primarily automated, continuously gathering intelligence and managing risks. Integrates automated risk prioritization and exposure detection.Partially automated or fully manual, depending on the scope and methodology. Typically, it involves human testers to perform assessments.

The Strategic Shift for Businesses

1. Risk Qualification and Prioritization

Many businesses rely solely on risk severity scores to determine what to patch first, but this approach fails to account for real-world impact. This means treating risks as isolated incidents instead of interconnected events that can affect key business functions. 

Instead of focusing solely on vulnerabilities with high severity scores, BAS contextualizes security and business KPAs to pinpoint those areas most likely to disrupt critical operations to help you prioritize remediation efforts based on operational resilience and business survival. 

2. Building a Security-Conscious Culture: Security Shouldn’t Be an IT Problem

A common challenge in building a security-conscious culture is the disconnect between compliance training and actual decision-making. While employees know compliance requirements, they often lack the real-time context to understand how their actions affect the organization’s security posture, conditioning reactive behavior instead of proactive. 

Experiencing the vulnerabilities firsthand through breach and attack simulations enables them to move beyond mere compliance to a culture where security is ingrained in daily work, fostering shared responsibility for security across the entire organization from the ground up.

3. Continuous Validation Structures: Stop Fixing Problems, Start Preventing Them

Traditional security validation is periodic—pentests, audits, and scans at set intervals. The downside, the security landscape changes quickly, and vulnerabilities introduced between tests are often left unaddressed. Such detection models allow small, undetected issues to compound, exposing you to a flurry of chained attacks or worse, death from a thousand cuts.

Thus, by constantly challenging the organization’s defenses through simulated attacks and CTEM metrics, businesses ensure their security posture adapts in real-time.

Future of Breach and Attack Simulation

Initially valued at $305.6 million in 2021, the global automated breach and attack simulation market is projected to reach $5.5 billion by 2031, growing at a CAGR of 33.6% from 2022 to 2031. But what is the primary driving force?

AI-Driven BAS:

  • Predictive Capabilities: AI will evolve to analyze threat data, internal logs, and public information further to predict attack vectors before they are exploited. Therefore, the focus will be on proactive patching and mitigation.
  • Autonomous Attack Simulations: AI agents will continue to continuously adapt and execute real-world attack patterns, eliminating the need for manual testing for low-hanging fruits and for vulnerabilities that do not require the creativity of humans to be uncovered.
  • Adaptive Defense Validation: AI will refine testing scenarios in real-time, mimicking adversary tactics to strengthen security defenses.
  • Intelligent Automation & Orchestration: AI will evolve to autonomously correlate vulnerabilities, prioritize risks, and trigger remediation workflows.

Threat Modelling Integration:

  • Contextualized Attacks: Simulating real-world TTPs from actual threat actors relevant to the organization’s specific risk profile.
  • Real-time Threat Simulation: Incorporating threat feeds to simulate emerging threats almost immediately.
  • Targeted Attack Simulation: Modeling attacks based on specific threat actors and their known methods.
  • Enhanced Realism: Moving beyond generic attacks to simulate sophisticated, multi-stage campaigns.

Common Challenges in Implementing BAS

Common Challenges in Implementing BAS

1. Mimicking Advanced Threat Actors Accurately

One of the primary challenges in implementing BAS is accurately mimicking the tactics, techniques, and procedures (TTPs) of advanced threat actors. Even with breach and attack simulation tools, the complexity of real-world adversaries—including their ability to adapt and evolve—can make replicating them in a controlled environment difficult. 

To address this, choose BAS solutions that continuously update and refine attack simulations based on evolving threat intelligence. Partnering with threat researchers or using AI-driven BAS platforms can enhance attack simulation accuracy by incorporating insights from real-time global threat landscapes.

2. Blind Spots in Non-Traditional Environments (IoT Devices)

With the increasing proliferation of IoT devices, organizations face difficulty securing these often overlooked, non-traditional environments. Due to their wide variety and unique vulnerabilities, they can introduce blind spots in security systems, as even BAS tools may not always be capable of covering these devices comprehensively.

Implement a layered security approach combining BAS with IoT-specific vulnerability scanning and monitoring tools. Regularly monitoring IoT environments, such as firmware vulnerabilities or proprietary protocols, coupled with manual pentesting, can help close the security gaps that automated solutions might miss.

3. Limits of Automation

While automation in BAS offers significant speed and scalability benefits, it also has inherent limitations. Automated tools may not always capture the nuance of human decision-making or the adaptability of a sophisticated attack, thus, struggling to account for the complexities of the human factor in cyber attacks, such as social engineering tactics or unpredictable behaviors.

To mitigate these limits, supplement automated BAS with periodic manual red teaming exercises. Combining automated and human-driven testing ensures a more holistic approach, providing the depth and adaptability needed to catch sophisticated attack strategies that automation alone might miss.

4. Integration with Existing Security Frameworks

As many companies continue to employ legacy systems or have a patchwork of disparate security solutions that don’t communicate well with each other. Thus, BAS tools often need customizations to integrate smoothly with existing firewalls, SIEM systems, and vulnerability management platforms, which can lead to complications and delays during implementation.

The key here is to select tools that offer flexible integration capabilities, breach and attack simulation use cases, and robust API support. You should also prioritize establishing transparent workflows between their existing systems to create an integration roadmap that includes testing, monitoring, and continuous improvement.

Astra Pentest is built by the team of experts that helped secure Microsoft, Adobe, Facebook, and Buffer


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Final Thoughts

The traditional “fortress mentality” in cybersecurity—building walls and hoping for the best—is demonstrably failing, while compliance checklists and periodic assessments offer a false sense of security, leaving organizations vulnerable to modern attacks.  Thus, breach and attack simulation offers a critical paradigm shift, moving beyond reactive security to proactive defense. 

It forces organizations to confront their security assumptions, prioritize vulnerabilities based on business impact, and foster a culture of continuous improvement.  While implementation presents challenges, the future of bas simulation, driven by AI and threat intelligence, offers the best chance to minimize damage, maintain operational resilience, and, ultimately, stay ahead of the curve.

FAQs

What is Breach and Attack Simulation (BAS)? 

Breach and Attack Simulation (BAS) is a proactive, real-time adversarial testing framework that continuously emulates attacker behaviors across the digital landscape. It provides an ongoing, dynamic security posture assessment by simulating APTs, insider threats, and emerging attack vectors in a controlled environment.

What is the difference between BAS and pentesting?

BAS continuously simulates real-world attacks to identify security gaps and validate defenses, offering ongoing insights. Pentesting is a periodic, manual assessment focused on discovering vulnerabilities at a specific point in time, providing deeper but less frequent analysis.

What is the difference between CTEM and BAS?

CTEM is a continuous, risk-based approach to identifying and mitigating threats across an organization’s attack surface, while BAS simulates real-world attacks to test defenses. CTEM is ongoing and strategic; BAS is periodic and tactical.