What Is a BAS Assessment?

LAST UPDATED: December 26, 2023

Picus Labs   By Picus Labs  •  October 12, 2023, 12 min read

As the threat landscape continuously evolves, organizations overwhelmed by vast amounts of cyber threat intelligence on emerging threats targeting their region and industry struggle to keep up with the latest malware, attack campaigns, and their TTPs (tactics, techniques, and procedures). Consequently, they often assume the effectiveness of their defense layers, leading to a false sense of security and leaving vulnerabilities unaddressed. Recognizing this, we at Picus Security underscore the importance of conducting Breach and Attack Simulation (BAS) assessments to obtain data-driven insights into security posture and prioritize mitigation actions.

In this blog, we discuss what a BAS assessment entails, the benefits of regular BAS assessments, how it differs from traditional security assessment methods, and how the Picus Complete Security Validation Platform offers BAS assessment capabilities to its users.

What Is a BAS Assessment?

A BAS assessment is a proactive approach to evaluating the effectiveness of implemented security controls by simulating a range of cyberattacks on an organization's systems, applications, and networks. This method aims to identify vulnerabilities and weaknesses before actual attackers do, providing insights and actionable recommendations for improving the overall security posture.

BAS assessments enable organizations to conduct secure attack simulations in their environment using placed agents, without causing any disruption to real domain-joined assets. Through these simulations, organizations gain data-driven insights into how their security solutions, including NGFW, IPS and IDS, WAF, Mail Security, and Proxy solutions respond to potential attacks.

What Are the Benefits of BAS Assessment?

Breach and Attack Simulation (BAS) assessments hold paramount importance in the cybersecurity domain for several reasons:

  • Proactive Security Enhancement with BAS Assessments

Unlike traditional security measures that often react to incidents after they occur, BAS assessments allow organizations to be proactive. By simulating attacks on their selected systems, they can pinpoint vulnerabilities and address them before they are exploited by malicious actors.

A core and crucial aspect of making BAS assessments a proactive practice is maintaining an up-to-date threat library. This allows organizations to select the emerging threat from the library, test its impact in their environment, determine how effectively the attack is blocked, or if it's not blocked, ascertain if it's detected and if an alert has been generated. Following this, good BAS assessment vendors provide mitigation recommendations, especially vendor-specific suggestions where an immediate patch is nonexistent or not applicable.

Figure. Picus Complete Security Control Validation Emerging Threat Templates

For instance, in October 2023, at the time of writing this blog, a local privilege escalation vulnerability affecting major Linux distributions was disclosed [1]. CVE-2023-4911 is a buffer overflow vulnerability found in GNU C Library's dynamic loader and has a CVSS score of 7.8 (High). Adversaries may gain full root privileges in Fedora, Ubuntu, and Debian systems when they exploit the CVE-2023-4911 vulnerability. Organizations are advised to update their vulnerable Linux systems as soon as possible.

Figure 1. Threat Library from the Picus Complete Security Control Validation Platform

At Picus Security, our expert red team engineers within the specialized division of Picus Labs have rapidly integrated the relevant threat associated with CVE-2023-4911 into our comprehensive threat library. Leveraging this update, our customers can now conduct detailed attack simulations to assess and validate the robustness of their cybersecurity controls against potential exploitation techniques tied to CVE-2023-4911. This proactive approach ensures they can mitigate vulnerabilities before they are actively exploited by malicious actors in the cyber landscape. After the simulation is conducted, vendor-based mitigation signatures are provided so that our customers are not just left with the fact that their implemented security measures are not functioning as expected. 

By conducting a BAS assessment for the specific threat, organizations can proactively pinpoint vulnerabilities in their security posture. They can then proceed with the available patching process or implement the vendor-specific mitigation suggestions provided by the platform.

  • Continuous Security Validation through BAS Assessments 

In today's rapidly-evolving digital environment, vulnerabilities can surface unexpectedly. BAS (Breach and Attack Simulation) offers a proactive approach to security by continuously validating the effectiveness of both prevention and detection mechanisms.

On the prevention front, BAS supports controls such as Firewalls, Next-Gen Firewalls (NGFW), Web Application Firewalls (WAF), Intrusion Prevention Systems (IPS), Endpoint Protection Platforms (EPP), and Secure Email and Web Gateways (SEG). These controls are rigorously tested to ensure they prevent vulnerability exploitation attacks, guard against web application attacks, and effectively block malicious incoming and outgoing traffic, including command and control activities, malicious file downloads, and data exfiltration.

On the detection side, BAS emphasizes the importance of robust Security Incident and Event Management (SIEM) systems, Incident Prevention System (IPS), Endpoint Detection and Response (EDR), and Extended Detection and Response (XDR). These systems are validated to guarantee that logs and telemetry are captured and parsed accurately, security events are time stamped correctly, and correlation rules are in place to generate timely alerts. Crucially, these controls ensure that alerts are generated swiftly upon detecting malicious behavior.

With conducting regular BAS assessments, organizations can be assured of a robust and adaptive security posture, ready to counter the latest threats and vulnerabilities.

  • Objective Measurement with BAS Assessments

BAS assessments are instrumental in delivering an objective assessment of an organization's security infrastructure. These assessments proactively provide quantifiable data on the robustness of security controls against an array of simulated cyber-attacks. This tangible data becomes a crucial pillar for making strategic, data-driven decisions to fortify security.

The Picus Security Control Validation module stands out by leveraging BAS assessments to provide a multifaceted perspective on security effectiveness. Through simulating real-world threats, it thoroughly assesses the ability of an organization's security readiness against both known threats and emerging threats.

  • For instance, when looking at prevention metrics, the percentages give a direct quantitative insight into the adequacy of security defenses. 

  • However, a BAS assessment's real value on the detection front is assessed not just by the capability to identify threats but, crucially, in ensuring immediate and accurate alerting. If threats are logged without concurrent alerts, it's an immediate call to action, underscoring the need for system recalibration.

To sum it up, Picus' BAS assessments are more than just evaluative tools; they're strategic assets. They arm organizations with rigorous, data-centric insights, guiding the continuous refinement of security controls to ensure they remain at the pinnacle of effectiveness in a dynamic cyber threat landscape.

  • Optimized Resource Allocation with BAS Assessment

Optimized resource allocation stands out as one of the key advantages of BAS assessments. In a cybersecurity landscape that's both intricate and perpetually shifting, organizations grapple with the dual challenge of defending against threats and ensuring efficient use of available resources. 

BAS assessments play a pivotal role in this balancing act. By generating real-time, actionable data on the organization's vulnerabilities, they pave the way for informed decision-making. Instead of spreading resources thinly over a broad spectrum, or worse, operating based on assumptions, security teams can focus their efforts where they matter most. This leads to a targeted approach, ensuring that the most pressing vulnerabilities are addressed first. 

Moreover, by aligning security investments with actual threat assessments, organizations can maximize the return on their cybersecurity investments, ensuring robust protection without unnecessary expenditure. 

In essence, BAS assessments empower organizations to do more with less, turning insights into strategic actions that bolster cybersecurity while optimizing resource use.

How Does BAS Differ from Traditional Vulnerability Assessments and Penetration Testing?

Breach and Attack Simulation (BAS) emerges as a solution to many of the challenges associated with traditional security assessments and methods. The limitations of these conventional approaches underscore the need for a more evolved strategy. 

  • Traditional assessments, such as penetration testing, vulnerability scanning, and red teaming, often provide an incomplete and point-in-time picture of an organization's security landscape. Both an organization's IT infrastructure and the threat landscape are always changing. Hence, point-in-time assessments can become ineffective in just a matter of days.

  • Traditional security assessment practices’ manual nature makes them time-consuming and limits their scope, often restricting their purview to specific networks or systems. 

  • While vulnerability scanning casts a wider net, interpreting its results can be daunting, and prioritizing threats becomes a challenge.

  • Red teaming, which emulates real-world attack scenarios, offers deeper insights but is neither scalable nor continuous, making it an expensive option. 

  • Meanwhile, threat intelligence, though invaluable, poses its own challenges. Many organizations struggle to operationalize the vast amount of data it produces, leading to potential oversight of critical details. This overwhelming influx of data sometimes results in a passive, reactive stance, where security teams grapple with myriad alerts, often without clear prioritization.

Adding to the conundrum, merely pumping more funds into security technology doesn't guarantee improved protection. Without a clear understanding of emerging threats, investments can be misdirected, leading to redundancy or, worse, gaping vulnerabilities. 

Also, merely deploying more security controls doesn't reduce risk if their effectiveness isn't continually evaluated.  These challenges underscore the need for BAS, an approach that promises continuous, holistic, and actionable insights into an organization's security posture.

Comparison Table for BAS vs. Traditional Security Assessment Methods

Below, you will see a table that compares BAS solutions to traditional assessment methods, such as red teaming, penetration testing and vulnerability scanning.

Breach and Attack Simulation (BAS) refers to a modern approach to cybersecurity testing that contrasts with traditional methods like vulnerability assessments and penetration testing. 

  • Unlike these conventional techniques, BAS is fully automated, offering consistent and continuous assessments of an organization's security posture. This automation ensures that security controls are consistently validated for effectiveness. 

  • Furthermore, BAS assessments are adept at simulating attacks targeting specific Common Vulnerabilities and Exposures (CVEs) and conduct tests throughout the entire cyber kill chain. It provides actionable mitigation insights for security controls and facilitates the quicker adoption of security frameworks. 

  • Additionally, BAS assessments offer quantifiable metrics, enabling organizations to measure and track their security improvements. Importantly, it safely assesses production environments without causing disruptions or risks. 

  • In contrast, traditional methods might be manual, periodic, and might not cover the full spectrum of potential threats, sometimes posing some risks when assessing live environments.

How Often Should Organizations Conduct BAS Assessments?

Continuous Breach and Attack Simulation (BAS) assessments are pivotal in today's rapidly changing IT environment. Their continuous nature ensures that as organizations make frequent updates to applications and configurations, any introduced vulnerabilities are promptly identified. This continuous testing reflects the transient nature of threats, offering immediate feedback and enabling swift remediation. With cyber threats evolving daily and the increasing sophistication of Advanced Persistent Threats (APTs), waiting for periodic assessments can leave organizations vulnerable for extended periods. Moreover, continuous BAS assessments enhance IT teams' training and awareness, ensuring a proactive stance and a consistently robust security posture against emerging challenges.

Below, you will find the key reasons and benefits of conducting continuous BAS assessments.

  • Cyber threats landscape is not static, continuously evolving with more sophisticated malware campaigns, including at least 10 TTPs on average.  

  • New zero-day vulnerabilities, advanced persistent threats (APTs), and evolving malware campaigns emerge frequently. 

  • BAS assessment solutions offer an ROI and feature a threat library that is continuously updated through in-depth cyber threat intelligence (CTI) research by dedicated red team engineers. The threats added to this library are meticulously tested to ensure they are safe and non-disruptive while mimicking the real-life behaviors of the simulated attack kill chain.

  • With continuous BAS, an organization can rapidly simulate this new attack technique to ensure its security controls can effectively detect and mitigate such a threat.

  • Provides data-driven insights into the effectiveness of implemented security controls and their readiness against both known and unknown threats.

  • Provides visibility into the security posture that necessitates immediate remediation and mitigation by the Blue team or defensive professionals, allowing for prioritized allocation of limited resources and time.

  • As security solutions update their signatures, rules, or heuristics, there's always a possibility of configuration drift or missed detections. For example, after updating an Intrusion Detection System (IDS) with a new set of rules, continuous BAS can simulate specific attack behaviors to confirm the IDS is correctly flagging malicious activities and not generating false negatives.

BAS Assessments with Picus Security Control Validation Platform

Picus Security Control Validation (SCV), a component of the Complete Security Control Validation platform powered by the award-winning Breach and Attack Simulation (BAS) technology, helps you measure and enhance cyber resilience by automatically and continuously testing the effectiveness of your security tools.


Let's delve into how Picus’ Security Control Validation platform conducts a BAS assessment. 

For this example, we'll execute a comprehensive Network Infiltration attack simulation featuring 61 distinct threats, though we won't list them all here (Check the figure below). As of this blog's publication, we've included threats frequently observed in the wild.


Figure. Threats Included into an Arbitrary Attack Simulation

After choosing the agent and configuring the settings, you can either initiate the simulation immediately or set it for a later time. For this demonstration, we'll start the simulation right away. Once completed, a detailed report is generated


In our  BASassessment of the "Network Infiltration Attacks" module, it is evident that out of 61 network threats, our security controls successfully blocked 41. Nonetheless, 20 threats managed to bypass these controls. This data indicates a 67% success rate in prevention but highlights the need for refining our security controls and implementing further mitigations. 

Furthermore, it's pertinent to mention that the determination of a threat being blocked or otherwise hinges on the interruption of its inherent attack actions. It's worth noting that a single threat could encompass multiple attack actions or just one.


Under the "Attacker's Objective" focused on "Delivery", various variants of the Monti Ransomware were introduced into the simulation. 

As depicted in the graphic, there's a mixed result: certain actions associated with the ransomware variants were successfully intercepted, while others bypassed our security. More concerningly, some unblocked actions went undetected without any logging by our detection systems. Given this combination of outcomes, we classify this particular threat as both undetected and unblocked.


By selecting, say, Variant-2, you can access its associated vendor-specific preventive mitigation signature. As depicted in the following figure, we present signatures from a range of vendors. Furthermore, we highlight which of your security controls failed to log the attack actions, granting you insight into the efficacy of your rules.

In conclusion, the Picus Security Control Validation (SCV), a pivotal component of the Complete Security Control Validation platform, harnesses the innovative Breach and Attack Simulation (BAS) technology to continuously assess and improve cybersecurity resilience. Our in-depth Network Infiltration attack simulation showcases both the strengths and vulnerabilities of currently implemented security controls. Distinct threats, like variants of Monti Ransomware, highlight gaps in detection and prevention capabilities. By providing a detailed view of vendor-specific mitigation signatures and spotlighting inefficiencies in security controls, Picus SCV equips organizations with the essential insights to continually refine and bolster their cyber defenses.

Frequently Asked Questions (FAQs)
Here are the most frequently asked questions about BAS Assessment.
What Is Breach and Attack Simulation Software?
Breach and Attack Simulation (BAS) software is a modern cybersecurity solution that automatically evaluates an organization's security posture. It simulates cyberattacks on the organization's systems, networks, and applications without causing harm, aiming to identify vulnerabilities and potential weaknesses before real attackers do.
What Is Breach and Attack Simulation by Gartner?
Gartner is a leading research and advisory company. In the context of BAS, Gartner defines Breach and Attack Simulation as tools that help businesses understand their security posture by automating the simulation of a range of cyberattacks against their infrastructures, thereby testing the efficacy of their security controls.
What Is a Breach Attack?
A breach attack refers to a successful attempt by unauthorized individuals or entities to bypass an organization's security measures, gaining access to protected systems, data, or networks. Such attacks aim to steal, manipulate, or destroy sensitive information or disrupt services.
How Does a BAS Tool Work?
A BAS tool works by simulating real-world cyberattacks on an organization's digital infrastructure. It safely imitates the tactics, techniques, and procedures (TTPs) of potential attackers, assessing the effectiveness of existing security controls. Upon completion, the tool provides insights and recommendations for fortifying defenses, ensuring the organization remains resilient against actual cyber threats.
Please click here to see the references

[1] S. Abbasi, "CVE-2023-4911: Looney Tunables - Local Privilege Escalation in the glibc's ld.so," Qualys Security Blog, Oct. 03, 2023. Available: https://blog.qualys.com/vulnerabilities-threat-research/2023/10/03/cve-2023-4911-looney-tunables-local-privilege-escalation-in-the-glibcs-ld-so. [Accessed: Oct. 11, 2023]

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Understand the 4 trade-offs limiting security teams in managing their organization's threat exposure.