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Threat Modelling

Task 1  Introduction

Amid an ever-evolving threat landscape, is your organisation prepared to mitigate potential risks? Do you proactively identify vulnerabilities, prioritise threats, and implement security measures to safeguard your critical assets? How does your approach to managing security risks contribute to maintaining customer trust?

These questions arise when you consider the importance of threat modelling in today’s rapidly changing cyber security landscape. When confronted with a sophisticated threat actor, are you confident in your team’s ability to neutralise it effectively, or will these actors succeed in achieving their goals?

Learning Objectives

In this room, we will learn to apply different threat modelling frameworks for reducing potential risks in an organisational landscape. In addition, we will tackle topics such as the following throughout the room:

  • Significance of threat modelling in building an organisation’s resiliency from threats.
  • Fundamentals of modelling a significant threat applicable to your organisation for emulation purposes.
  • Learn different threat modelling frameworks like MITRE ATT&CK, DREAD, STRIDE and PASTA.

Prerequisites

It is suggested to clear the following rooms first before proceeding with this room:

  • Intro to Threat Emulation (coming soon!)
  • Principles of Security

Task 2  Threat Modelling Overview

As we dive into this topic, let’s briefly define threat modelling to ensure a comprehensive understanding.

What is Threat Modelling?

Threat modelling is a systematic approach to identifying, prioritising, and addressing potential security threats across the organisation. By simulating possible attack scenarios and assessing the existing vulnerabilities of the organisation’s interconnected systems and applications, threat modelling enables organisations to develop proactive security measures and make informed decisions about resource allocation. 

Threat modelling aims to reduce an organisation’s overall risk exposure by identifying vulnerabilities and potential attack vectors, allowing for adequate security controls and strategies. This process is essential for constructing a robust defence strategy against the ever-evolving cyber threat landscape.

Threat, Vulnerability and Risk

As mentioned above, the main goal of threat modelling is to reduce the organisation’s risk exposure. So before we deep dive into its application, let’s review first the definitions of Threat, Vulnerability and Risk.

TypeDefinition
ThreatRefers to any potential occurrence, event, or actor that may exploit vulnerabilities to compromise information confidentiality, integrity, or availability. It may come in various forms, such as cyber attacks, human error, or natural disasters.
VulnerabilityA weakness or flaw in a system, application, or process that may be exploited by a threat to cause harm. It may arise from software bugs, misconfiguration, or design flaws.
RiskThe possibility of being compromised because of a threat taking advantage of a vulnerability. A way to think about how likely an attack might be successful and how much damage it could cause.

To simplify it, we can use an analogy of an organisation as a house and describe the potential threat, vulnerability and risk.

TypeAnalogy
ThreatOccurrence of someone breaking inside your home and taking all your belongings.
VulnerabilityWeaknesses in your home security, such as broken locks or open windows.
RiskLikelihood of being burglarised due to living in a neighbourhood with a high crime rate or a lack of an alarm system.
Representation of Threat, Vulnerability and Risk.

Understanding the differences between threat, vulnerability, and risk is essential for effective threat modeling. It enables the organisation to effectively identify and prioritise security issues, resulting in a faster way of reducing risk exposure.

High-Level Process of Threat Modelling

Before delving into different threat modelling frameworks, let’s briefly run through a simplified, high-level process.

  1. Defining the scopeIdentify the specific systems, applications, and networks in the threat modelling exercise.
  2. Asset IdentificationDevelop diagrams of the organisation’s architecture and its dependencies. It is also essential to identify the importance of each asset based on the information it handles,  such as customer data, intellectual property, and financial information.
  3. Identify ThreatsIdentify potential threats that may impact the identified assets, such as cyber attacks, physical attacks, social engineering, and insider threats.
  4. Analyse Vulnerabilities and Prioritise Risks Analyse the vulnerabilities based on the potential impact of identified threats in conjunction with assessing the existing security controls. Given the list of vulnerabilities, risks should be prioritised based on their likelihood and impact.
  5. Develop and Implement CountermeasuresDesign and implement security controls to address the identified risks, such as implementing access controls, applying system updates, and performing regular vulnerability assessments.
  6. Monitor and EvaluateContinuously test and monitor the effectiveness of the implemented countermeasures and evaluate the success of the threat modelling exercise. An example of a simple measurement of success is tracking the identified risks that have been effectively mitigated or eliminated.

By following these steps, an organisation can conduct a comprehensive threat modelling exercise to identify and mitigate potential security risks and vulnerabilities in their systems and applications and develop a more effective security strategy. 

Remember that the example above is a generic high-level process; threat modelling frameworks will be introduced in the following tasks.

Collaboration with Different Teams

The high-level process discussed above involves many tasks, so it is crucial to have multiple teams collaborate. Each unit offers valuable skills and expertise, helping improve the organisation’s security posture. By collaborating, organisations can effectively address and align the security efforts needed to build a better defence.

In line with this, we will introduce the teams typically involved in a threat modelling Exercise.

TeamRole and Purpose
Security TeamThe overarching team of red and blue teams. This team typically lead the threat modelling process, providing expertise on threats, vulnerabilities, and risk mitigation strategies. They also ensure security measures are implemented, validated, and continuously monitored.
Development TeamThe development team is responsible for building secure systems and applications. Their involvement ensures that security is always incorporated throughout the development lifecycle.
IT and Operations TeamIT and Operations teams manage the organisation’s infrastructure, including networks, servers, and other critical systems. Their knowledge of network infrastructure, system configurations and application integrations is essential for effective threat modelling.
Governance, Risk and Compliance TeamThe GRC team is responsible for organisation-wide compliance assessments based on industry regulations and internal policies. They collaborate with the security team to align threat modelling with the organisation’s risk management objectives.
Business StakeholdersThe business stakeholders provide valuable input on the organisation’s critical assets, business processes, and risk tolerance. Their involvement ensures that the efforts align with the organisation’s strategic goals.
End UsersAs direct users of a system or application, end users can provide unique insights and perspectives that other teams may not have, enabling the identification of vulnerabilities and risks specific to user interactions and behaviours.

Note that the list is not limited to these teams and may vary depending on your organisational structure. Moreover, the collaboration of these teams is not limited to threat modelling exercises, as they also work hand in hand in securing the organisation through different initiatives.

Attack Trees

In addition to the high-level methodology discussed above, creating an attack tree is another good way to identify and map threats.

An attack tree is a graphical representation used in threat modelling to systematically describe and analyse potential threats against a system, application or infrastructure. It provides a structured, hierarchical approach to breaking down attack scenarios into smaller components. Each node in the tree represents a specific event or condition, with the root node representing the attacker’s primary goal.

For a quick example, let’s use the diagram below that represents a scenario of an attacker trying to gain unauthorised access to sensitive data stored in a cloud-based storage system.

Attack Tree representation of Gain unauthorised access to sensitive data.

In this diagram, the root node represents the attacker’s primary goal: gain unauthorised access to sensitive data. The first level of child nodes represents different high-level strategies an attacker might do to achieve the goal. Each node further breaks down into specific steps, detailing the attacker’s possible techniques and actions.

In addition to the traditional hierarchical structure, attack trees can be organised as attack paths, which depict the possible routes or sequences of vulnerabilities a threat actor can exploit to achieve their goal. Attack paths are essentially chains of vulnerabilities that are interconnected.  

In an attack path representation, the initial starting node represents the attacker’s entry point into the system or network. From there, the various branches or nodes represent the specific vulnerabilities, attack vectors, or steps the threat actor can follow to advance towards their objective.

Task 3  Modelling with MITRE ATT&CK

After having a good overview of threat modelling concepts, let’s start with the first framework of this room – the MITRE ATT&CK Framework. 

MITRE ATT&CK Framework

For a quick refresher, let’s define MITRE ATT&CK again. 

MITRE Logo.

MITRE ATT&CK (Adversarial Tactics, Techniques, and Common Knowledge) is a comprehensive, globally accessible knowledge base of cyber adversary behaviour and tactics. Developed by the MITRE Corporation, it is a valuable resource for organisations to understand the different stages of cyber attacks and develop effective defences.

The ATT&CK framework is organised into a matrix that covers various tactics (high-level objectives) and techniques (methods used to achieve goals). The framework includes descriptions, examples, and mitigations for each technique, providing a detailed overview of threat actors’ methods and tools.

For a quick example, let’s examine one of the techniques in the framework – Exploit Public-Facing Application.

As you can see in the provided link, the page contains five significant sections, namely:

  1. Technique Name and DetailsInformation such as name, detailed explanation of the technique, types of data or logs that can help or detect, and platforms (Windows, MacOS, Linux) relevant to the technique.Name and Details under the Exploit Public-Facing Application technique.
  2. Procedure ExamplesReal-world examples of how threat actors have employed the technique in their adversarial operations.Procedure Examples showing usage of Exploit Public-Facing Application technique.
  3. Mitigations
    Recommended security measures and best practices to protect against the technique.Mitigations or ways to prevent Exploit Public-Facing Application technique.
  4. Detections Strategies and indicators that can help identify the technique, as well as potential challenges in detecting the technique.Examples of ways to detect Exploit Public-Facing Application technique.
  5. References 
    External sources, reports, and articles that provide additional information, context, or examples related to the technique.List of additional references for Exploit Public-Facing Application technique.

By exploring the contents of a MITRE ATT&CK technique page, you may gain valuable insights into the specific methods employed by an adversary and enhance your organisation’s overall security posture by implementing the suggested mitigations and detection strategies.

Applying MITRE ATT&CK in Threat Modelling Process

MITRE ATT&CK can be integrated into our threat modelling process by mapping the identified threats and vulnerabilities to the tactics and techniques described in the ATT&CK Framework. We can insert a new entry in our methodology after the “Identify Threats” step.

  • Identify ThreatsIdentify potential threats that may impact the identified assets, such as cyber attacks, physical attacks, social engineering, and insider threats.
  • Map to MITRE ATT&CK Map the identified threats to the corresponding tactics and techniques in the MITRE ATT&CK Framework. For each mapped technique, utilise the information found on the corresponding ATT&CK technique page, such as the description, procedure examples, mitigations, and detection strategies, to gain a deeper understanding of the threats and vulnerabilities in your system.

Incorporating the framework in our threat modelling process ensures a comprehensive understanding of the potential security threats. It enables a better application of countermeasures to reduce the overall risk to your organisation.

Utilising MITRE ATT&CK for Different Use Cases

Aside from incorporating MITRE ATT&CK in a threat modelling process, MITRE ATT&CK can be used in various cases depending on your organisation’s needs. To wrap up this task, here is a list of some use cases for utilising this framework.

  1. Identifying potential attack paths based on your infrastructureBased on your assets, the framework can map possible attack paths an attacker might use to compromise your organisation. For example, if your organisation uses Office 365, all techniques attributed to this platform are relevant to your threat modelling exercise.
  2. Developing threat scenariosMITRE ATT&CK has attributed all tactics and techniques to known threat groups. This information can be leveraged to assess your organisation based on threat groups identified to be targeting the same industry.
  3. Prioritising vulnerability remediationThe information provided for each MITRE ATT&CK technique can be used to assess the significant impact that may occur if your organisation experiences a similar attack. Given this, your security team can identify the most critical vulnerabilities to address.

Note that the usage of this framework is not limited to the provided use cases above. It is still under your discretion how to utilise the information provided by the framework effectively.

To improve the overall threat modelling process with MITRE ATT&CK, let’s integrate the usage of ATT&CK Navigator in mapping the threats identified on the following task.

Task 4  Mapping with ATT&CK Navigator

ATT&CK Navigator

Before discussing the ATT&CK Navigator, you may start the machine attached to this room by clicking the Start Machine button. Once the machine is up, access the ATT&CK Navigator webpage via the AttackBox or VPN using this link – http://MACHINE_IP. You will see this landing page once you access the provided link.

ATT&CK Navigator landing page upon access.

Note: This open-source application is also accessible via this link. However, we will use the provided VM to have consistency in the ATT&CK Navigator version used in this task.

Now that the web application is running, let’s discuss the MITRE ATT&CK Navigator!

The MITRE ATT&CK Navigator is an open-source, web-based tool that helps visualise and navigate the complex landscape of the MITRE ATT&CK Framework. It allows security teams to create custom matrices by selecting relevant tactics and techniques that apply to their specific environment or threat scenario.

This task will have a walkthrough on creating a layer and mapping the relevant techniques for your threat modelling exercise. Here is a brief overview of the steps and features we will utilise.

  1. Creation of a new layer.
  2. Searching and selecting techniques.
  3. Viewing, sorting and filtering layers.
  4. Annotating techniques with fills, scores and comments.

Creating a New Layer

To start with, let’s create a new layer and choose enterprise. 

Creation of a new layer - Enterprise Matrix.

You may have observed that there are three options for creating a new layer. These layers pertain to the three MITRE ATT&CK matrices, namely:

  • Enterprise – The Enterprise Matrix focuses on threats and techniques commonly used against enterprise networks.
  • Mobile – The Mobile Matrix focuses on threats and techniques against mobile devices, such as smartphones and tablets.
  • ICS – The ICS Matrix focuses on threats and techniques against industrial control systems, which control critical infrastructure, such as power plants, water treatment facilities, and transportation systems.

We have chosen the Enterprise Matrix to cover threat actors’ typical techniques when targeting an organisation. After creating a new layer, you will have this view once the web page has loaded.

Initial view of all techniques under the Enterprise matrix.

Searching and Selecting Techniques

The first important feature we want to utilise in this application is the search functionality under the Selection Controls panel. This feature allows us to search and multi-select techniques you want to highlight or mark.

You may press the magnifier button to access the right sidebar, search using any keywords, or choose any selection under Techniques, Threat Groups, Software, Mitigations, Campaigns, or Data Sources.

Search functionality example usage.



For a quick example, search for APT41 and hover its entry on the Threat Groups section. You may observe that it will highlight all techniques attributed to this threat group. Once you click the select button, the highlighted techniques will be selected as a group and can be annotated with a score or a background fill, which will be discussed in the following instructions.

Techniques highlighted after searching APT41.

After selecting the threat group, you may also observe that the deselect button now has a numerical value. This indicates the current number of chosen techniques. You may press this button to remove all your current technique selections.

Deselect button representing the number of selected techniques.

Lastly, you may right-click any technique if you prefer to do an action on a single technique (e.g. select, add to selection, remove from selection).

Additional actions through right-click.

Viewing, Sorting and Filtering Layers

We will tackle the next set of features under the Layer Controls panel. However, we will only focus on the following:

  • Exporting features (download as JSON, Excel, SVG) – This allows you to dump the selected techniques, including all annotations. The data exported can be ingested again in the ATT&CK Navigator for future use.
  • Filters – Allows you to filter techniques based on relevant platforms, such as operating systems or applications. For a quick example, the image below shows all techniques that are attributed to Office365.
Filtered list of techniques with O365 filter.
  • Sorting – This allows you to sort the techniques by their alphabetical arrangement or numerical scores. The image below shows that all techniques are arranged alphabetically.
Example usage of sorting the techniques.
  • Expand sub-techniques – View all underlying sub-techniques under each technique, expanding the view for all techniques. You will have a similar view with the image below once you have expanded the sub-techniques.
Expanding all sub-techniques in one view.

Annotating Techniques

Now, the last set of features is under the Technique Controls panel. These buttons allow you to annotate details on selected techniques. For a quick run-through, here are the features under the panel mentioned (from left to right):

Buttons under the technique controls.
  • Toggle state – This feature allows you to disable the selected techniques, making their view greyed-out.
Example usage of a toggle button.
  • Background color – This allows you to change the background color of the selected technique, for highlighting and grouping purposes.
Example usage of changing the background colours of the techniques.
  • Scoring – Allows you to rate each technique or set of techniques based on criteria depending on your needs, such as the impact of a technique.
  • Comment – Allows you to add notes and observations to a technique.
  • Link – Allows you to add external links, such as additional references related to the technique.
  • Metadata – Allows you to add custom tags and labels to a particular technique.
  • Clear annotations on selected – Remove all annotations on selected techniques.

The image below is an example of using Scoring, Comment, Link and Metadata features.

Adding metadata on a single technique.

Utilising ATT&CK Navigator

To put the concepts of this framework into practice, let’s use the following scenario below.

You are tasked to utilise the MITRE ATT&CK framework for your threat modelling exercise. The organisation you’re currently working with is in the financial services industry. Given that, some known threat groups targeting this industry are:

  • APT28 (Fancy Bear)
  • APT29 (Cozy Bear)
  • Carbanak
  • FIN7 (Carbanak/Fancy Bear)
  • Lazarus Group

In addition, your organisation uses the following technologies:

  • Google Cloud Platform (GCP) for cloud infrastructure
  • Online banking platform developed by internal developers
  • A Customer Relationship Management (CRM) platform

Lastly, the critical assets that you handle based on your business stakeholders are the following:

  • Customer financial data
  • Transaction records
  • Personally identifiable information (PII)

Given this scenario, you can use the MITRE ATT&CK framework and ATT&CK Navigator to map and understand the significant techniques attributed to the provided threat groups and those affecting GCP and web applications.

View filtered with APT28 techniques.

Techniques used by APT28

Techniques related to GCP.

Techniques related to Google Cloud

Once these techniques are identified, you should prioritise the potential vulnerabilities that may affect the systems that handle your critical assets (financial data, transaction records, and PII). Some of the techniques that you may consider prioritising are the following:

  • Exploit Public-Facing Application (T1190) – Securing the public-facing application is crucial to prevent unauthorised access attempts.
  • Exploitation for Privilege Escalation (T1068) – The prevention of escalating attackers’ privileges reduces the chances of obtaining critical data only accessible to administrators.
  • Data from Cloud Storage (T1530) – Since the cloud instance contains critical data, safeguarding the confidentiality and integrity of the data stored is crucial.
  • Network Denial of Service (T1498) – The technique may not directly target the critical data within the cloud instance. Still, it can lead to service disruptions and potential impacts on the availability and accessibility of the data.

Now that we have identified these, the next step for the threat modelling exercise is to remediate and apply appropriate security controls to reduce the potential attack surface of our organisation.

Task 5  DREAD Framework

What is the DREAD Framework?

The DREAD framework is a risk assessment model developed by Microsoft to evaluate and prioritise security threats and vulnerabilities. It is an acronym that stands for:

DREADDefinition
DamageThe potential harm that could result from the successful exploitation of a vulnerability. This includes data loss, system downtime, or reputational damage.
ReproducibilityThe ease with which an attacker can successfully recreate the exploitation of a vulnerability. A higher reproducibility score suggests that the vulnerability is straightforward to abuse, posing a greater risk.
ExploitabilityThe difficulty level involved in exploiting the vulnerability considering factors such as technical skills required, availability of tools or exploits, and the amount of time it would take to exploit the vulnerability successfully.
Affected UsersThe number or portion of users impacted once the vulnerability has been exploited.
DiscoverabilityThe ease with which an attacker can find and identify the vulnerability considering whether it is publicly known or how difficult it is to discover based on the exposure of the assets (publicly reachable or in a regulated environment).
Logo representation of each DREAD component.

The categories are commonly phrased with the following questions to ingest the definitions provided above quickly:

  • Damage – How bad would an attack be?
  • Reproducibility – How easy is it to reproduce the attack?
  • Exploitability – How much work is it to launch the attack?
  • Affected Users – How many people will be impacted?
  • Discoverability – How easy is it to discover the vulnerability?

Using the questions above assists in understanding each category and applying it in a risk-assessment context.

DREAD Framework Guidelines

As mentioned above, the DREAD framework is an opinion-based model that heavily relies on an analyst’s interpretation and assessment. However, the reliability of this framework can still be improved by following some guidelines:

  1. Establish a standardised set of guidelines and definitions for each DREAD category that provides a consistent understanding of how to rate vulnerabilities. This can be supported by providing examples and scenarios to illustrate how scores should be assigned under various circumstances.
  2. Encourage collaboration and discussion among multiple teams. Constructive feedback from different members aids in justifying the assigned scores, which can lead to a more accurate assessment.
  3. Use the DREAD framework with other risk-assessment methodologies and regularly review and update the chosen methods and techniques to ensure they remain relevant and aligned with the organisation’s needs.

By ensuring that these guidelines are strictly followed, organisations can reduce the subjective nature of the framework and improve the accuracy and reliability of their risk assessments.

Qualitative Analysis Using DREAD Framework

The DREAD Framework is typically used for Qualitative Risk Analysis, rating each category from one to ten based on a subjective assessment and interpretation of the questions above. Moreover, the average score of all criteria will calculate the overall DREAD risk rating. 

To understand how the scoring works, let’s put the concepts into practice by using a good scenario.

A software company has developed a new website and needs to assess the risk associated with various security threats. Your team has created a guideline for scoring each component of the DREAD framework, as shown below:

DREAD Score2.557.510
DamageMinimal infrastructure information disclosureMinimal information disclosure related to client dataLimited PII leakComplete data leak
ReproducibilityMultiple attack vectors requiring technical expertiseMinor customisation for public exploits neededLittle prerequisite technical skills needed to run the exploitUsers with public exploits can successfully reproduce the exploit
ExploitabilityAlmost no public exploits are available and need customisation of scriptsComplicated exploit scripts available in the wildMinimal technical skills are required to execute public exploitsReliable Metasploit module exists
Affected UsersAlmost none to a small subsetAround 10% of usersMore than half of the user baseAll users
DiscoverabilityThe significant effort needed to discover the vulnerability chains for the exploit to workRequires a manual way of verifying the vulnerabilityPublic scanning scripts not embedded in scanning tools existAlmost all known scanning tools can find the vulnerability

Given this guideline, we can assess some known vulnerabilities in the application. Below is an example of scoring provided for each vulnerability.

  1. Unauthenticated Remote Code Execution (Score: 8)
    • Damage (D): 10
    • Reproducibility (R): 7.5
    • Exploitability (E): 10
    • Affected Users (A): 10
    • Discoverability (D): 2.5
  2. Insecure Direct Object References (IDOR) in User Profiles (Score: 6.5)
    • Damage (D): 2.5
    • Reproducibility (R): 7.5 
    • Exploitability (E): 7.5
    • Affected Users (A): 10 
    • Discoverability (D): 5
  3. Server Misconfiguration Leading to Information Disclosure (Score: 5)
    • Damage (D): 0
    • Reproducibility (R): 10
    • Exploitability (E): 10
    • Affected Users (A): 0
    • Discoverability (D): 5

Now what’s left is to prioritise the vulnerabilities based on their score and apply mitigations to secure the application.

Task 6  STRIDE Framework

What is the STRIDE Framework?

The STRIDE framework is a threat modelling methodology also developed by Microsoft, which helps identify and categorise potential security threats in software development and system design. The acronym STRIDE is based on six categories of threats, namely:

CategoryDefinitionPolicy Violated
SpoofingUnauthorised access or impersonation of a user or system.Authentication
TamperingUnauthorised modification or manipulation of data or code.Integrity
RepudiationAbility to deny having acted, typically due to insufficient auditing or logging.Non-repudiation
Information DisclosureUnauthorised access to sensitive information, such as personal or financial data.Confidentiality
Denial of ServiceDisruption of the system’s availability, preventing legitimate users from accessing it.Availability
Elevation of PrivilegeUnauthorised elevation of access privileges, allowing threat actors to perform unintended actions.Authorisation

As you can see, the table above also provides what component of the CIA triad is violated. The STRIDE framework is built upon this foundational information security concept.

By systematically analysing these six categories of threats, organisations can proactively identify and address potential vulnerabilities in their systems, applications, or infrastructure, enhancing their overall security posture.

Logos of each STRIDE component.

To understand the framework better, let’s deep-dive into each category and discuss some examples.

  • Spoofing
    • Sending an email as another user.
    • Creating a phishing website mimicking a legitimate one to harvest user credentials.
  • Tampering
    • Updating the password of another user.
    • Installing system-wide backdoors using an elevated access.
  • Repudiation
    • Denying unauthorised money-transfer transactions, wherein the system lacks auditing.
    • Denying sending an offensive message to another person, wherein the person lacks proof of receiving one.
  • Information Disclosure
    • Unauthenticated access to a misconfigured database that contains sensitive customer information.
    • Accessing public cloud storage that handles sensitive documents.
  • Denial of Service
    • Flooding a web server with many requests, overwhelming its resources, and making it unavailable to legitimate users.
    • Deploying a ransomware that encrypts all system data that prevents other systems from accessing the resources the compromised server needs.
  • Elevation of Privilege
    • Creating a regular user but being able to access the administrator console.
    • Gaining local administrator privileges on a machine by abusing unpatched systems.

The examples above illustrate various scenarios in which the categories can occur, emphasising the importance of implementing robust security measures to protect against these threats.

A typical representation of results after using the STRIDE framework is via a checklist table, wherein each use case is marked based on what STRIDE component affects it. In addition, some scenarios may cover multiple STRIDE components.

ScenarioSpoofingTamperingRepudiationInformation DisclosureDenial of ServiceElevation of Privilege
Sending a spoofed email, wherein the mail gateway lacks email security and logging configuration.
Flooding a web server with many requests that lack load-balancing capabilities.
Abusing an SQL injection vulnerability.
Accessing public cloud storage (such as AWS S3 bucket or Azure blob) that handles customer data.
Exploiting a local privilege escalation vulnerability due to the lack of system updates and modifying system configuration for a persistent backdoor.

Threat Modelling With STRIDE

To implement the STRIDE framework in threat modelling, it is essential to integrate the six threat categories into a systematic process that effectively identifies, assesses, and mitigates security risks. Here is a high-level approach to incorporating STRIDE in the threat modelling methodologies we discussed.

  1. System DecompositionBreak down all accounted systems into components, such as applications, networks, and data flows. Understand the architecture, trust boundaries, and potential attack surfaces.
  2. Apply STRIDE CategoriesFor each component, analyse its exposure to the six STRIDE threat categories. Identify potential threats and vulnerabilities related to each category.
  3. Threat AssessmentEvaluate the impact and likelihood of each identified threat. Consider the potential consequences and the ease of exploitation and prioritise threats based on their overall risk level.
  4. Develop Countermeasures 
    Design and implement security controls to address the identified threats tailored to each STRIDE category. For example, to enhance email security and mitigate spoofing threats, implement DMARC, DKIM, and SPF, which are email authentication and validation mechanisms that help prevent email spoofing, phishing, and spamming.
  5. Validation and Verification
    Test the effectiveness of the implemented countermeasures to ensure they effectively mitigate the identified threats. If possible, conduct penetration testing, code reviews, or security audits.
  6. Continuous Improvement
    Regularly review and update the threat model as the system evolves and new threats emerge. Monitor the effective countermeasures and update them as needed.

By following this approach, you can effectively incorporate the STRIDE framework into your threat modelling process, ensuring a comprehensive analysis of potential security threats.

Application of STRIDE Framework

To apply the concepts discussed in this task, let’s simulate a scenario wherein we can use the STRIDE framework.

Scenario: Your e-commerce company is in the process of designing a new payment processing system. To ensure its security and minimise the risk of compromise, you are tasked to conduct a threat modelling exercise using the STRIDE framework. All your assets are stored in a secure cloud infrastructure developed by your system architects.

As the leader of this initiative, you will be working with different teams to create a thorough threat modelling plan. Together, you aim to identify potential security threats and protect your payment processing system, ensuring the safety of your customers’ information.

As a guide, here are the roles and responsibilities of the teams joining the initiative:

TeamRoles and Responsibilities
Development TeamResponsible for building systems and applications used by the organisation.
System Architecture TeamResponsible for designing the overall architecture of the cloud services used by the organisation.
Security TeamProvide expertise on threats, vulnerabilities, and risk mitigation strategies.
Business Stakeholder TeamProvides valuable input on critical assets and business processes, and ensures alignment between the initiative and the organisation’s strategic goals.
Network Infrastructure TeamManages the organisation’s network infrastructure, including servers and critical systems.

To start working, click on the green View Site button in this task to open the static site lab and start working on your preparation for the threat modelling exercise by following the provided instructions.

Task 7  PASTA Framework

What is the PASTA Framework?

PASTA, or Process for Attack Simulation and Threat Analysis, is a structured, risk-centric threat modelling framework designed to help organisations identify and evaluate security threats and vulnerabilities within their systems, applications, or infrastructure. PASTA provides a systematic, seven-step process that enables security teams to understand potential attack scenarios better, assess the likelihood and impact of threats, and prioritise remediation efforts accordingly.

This framework was created by Tony UcedaVélez and Marco Morana. They introduced the PASTA framework in their book “Risk Centric Threat Modeling: Process for Attack Simulation and Threat Analysis”, published in 2015.

Seven-Step Methodology

Similar to the high-level process discussed in the previous task, the PASTA framework covers a series of steps, from defining the scope of the threat modelling exercise to risk and impact analysis. Below is an overview of the seven-step methodology of the PASTA Framework.

The 7-step PASTA methodology diagram.
  1. Define the ObjectivesEstablish the scope of the threat modelling exercise by identifying the systems, applications, or networks being analysed and the specific security objectives and compliance requirements to be met.
  2. Define the Technical ScopeCreate an inventory of assets, such as hardware, software, and data, and develop a clear understanding of the system’s architecture, dependencies, and data flows.
  3. Decompose the ApplicationBreak down the system into its components, identifying entry points, trust boundaries, and potential attack surfaces. This step also includes mapping out data flows and understanding user roles and privileges within the system.
  4. Analyse the Threats 
    Identify potential threats to the system by considering various threat sources, such as external attackers, insider threats, and accidental exposures. This step often involves leveraging industry-standard threat classification frameworks or attack libraries.
  5. Vulnerabilities and Weaknesses Analysis
    Analyse the system for existing vulnerabilities, such as misconfigurations, software bugs, or unpatched systems, that an attacker could exploit to achieve their objectives. Vulnerability assessment tools and techniques, such as static and dynamic code analysis or penetration testing, can be employed during this step.
  6. Analyse the Attacks
    Simulate potential attack scenarios and evaluate the likelihood and impact of each threat. This step helps determine the risk level associated with each identified threat, allowing security teams to prioritise the most significant risks.
  7. Risk and Impact Analysis
    Develop and implement appropriate security controls and countermeasures to address the identified risks, such as updating software, applying patches, or implementing access controls. The chosen countermeasures should be aligned with the organisation’s risk tolerance and security objectives.

PASTA Methodology Guidelines

To effectively implement the PASTA framework and optimise its benefits, you may follow these practical guidelines for each step of the methodology.

Define the ObjectivesSet clear and realistic security objectives for the threat modelling exercise.Identify relevant compliance requirements and industry-specific security standards.
Define the Technical ScopeIdentify all critical assets, such as systems and applications, that handle sensitive data owned by the organisation.Develop a thorough understanding of the system architecture, including data flows and dependencies.
Decompose the ApplicationBreak down the system into manageable components or modules.Identify and document each component’s possible entry points, trust boundaries, attack surfaces, data flows, and user flows.
Analyse the ThreatsResearch and list potential threats from various sources, such as external attackers, insider threats, and accidental exposures.Leverage threat intelligence feeds and industry best practices to stay updated on emerging threats.
Vulnerabilities and Weaknesses AnalysisUse a combination of tools and techniques, such as static and dynamic code analysis, vulnerability scanning, and penetration testing, to identify potential weaknesses in the system.Keep track of known vulnerabilities and ensure they are addressed promptly.
Analyse the AttacksDevelop realistic attack scenarios and simulate them to evaluate their potential consequences.Create a blueprint of scenarios via Attack Trees and ensure that all use cases are covered and aligned with the objective of the exercise.
Risk and Impact AnalysisAssess the likelihood and impact of each identified threat and prioritise risks based on their overall severity.Determine the most effective and cost-efficient countermeasures for the identified risks, considering the organisation’s risk tolerance and security objectives.

These guidelines provide a foundation for effectively using the PASTA framework’s seven-step methodology. However, adapting and customising the approach according to your organisation’s unique needs and requirements is crucial.

Benefits of Using the PASTA Framework

This framework, being risk-centric, offers numerous benefits for organisations seeking to enhance their security posture through threat modelling.

  • The framework is adaptable to unique objectives and helps organisations align with compliance requirements by systematically identifying and addressing security risks while ensuring proper security controls are in place.
  • Like the other frameworks, PASTA fosters collaboration between stakeholders, such as developers, architects, and security professionals, promoting a shared understanding of security risks and facilitating communication across the organisation.
  • In addition, the PASTA methodology helps organisations meet compliance requirements by systematically identifying and addressing security risks and ensuring that appropriate security controls are in place.
  • Lastly, the primary reason to use PASTA is its comprehensive and systematic process, ensuring a thorough analysis of the entire risk landscape. Organisations can proactively address security risks by employing PASTA, tailoring the seven-step methodology to their unique needs, and maintaining a solid security posture.

Application of PASTA Framework

To apply the concepts discussed in this task, let’s simulate a scenario wherein we can use the PASTA framework.

Scenario: Your organisation is known for its online banking platform, catering to many users across the Asia Pacific region. To ensure its resiliency to potential threats, you are tasked to conduct a threat modelling exercise using the PASTA framework.

As the leader of this initiative, you will be working with different teams to create a thorough threat modelling plan. Together, you aim to identify potential security threats and protect your online banking platform, ensuring the safety of your customers’ information.

As a guide, here are the roles and responsibilities of the teams joining the initiative:

TeamRoles and Responsibilities
Development TeamResponsible for building systems and applications used by the organisation.
System Architecture TeamResponsible for designing the overall architecture of the cloud services used by the organisation.
Security TeamProvide expertise on threats, vulnerabilities, and risk mitigation strategies.
Business Stakeholder TeamProvides valuable input on critical assets and business processes, and ensures alignment between the initiative and the organisation’s strategic goals.

You must follow the seven-step PASTA process in choosing whom to approach for the information you need for this threat modelling exercise.

To start working, click on the green View Site button in this task to open the static site lab and start working on your preparation for the threat modelling exercise by following the provided instructions.

Task 8  Conclusion

Congratulations! You have completed the Threat Modelling room. 

To conclude the room, let’s summarise the use case applications of each framework:

FrameworkUse Case Applications
MITRE ATT&CKUnlike DREAD and STRIDE, which focus more on potential risks and vulnerabilities, ATT&CK provides a practical and hands-on approach by mapping adversary tactics.Assess the effectiveness of existing controls against known attack techniques used by threat actors.
DREADDREAD offers a more numerical and calculated approach to threat analysis than STRIDE or MITRE ATT&CK, making it excellent for clearly prioritising threats.
Qualitatively assess the potential risks associated with specific threats.Prioritise risk mitigation based on the collective score produced by each DREAD component.
STRIDEWhile other frameworks like MITRE ATT&CK focus on real-world adversary tactics, STRIDE shines in its structure and methodology, allowing for a systematic review of threats specific to software systems.
Analyse and categorise threats in software systems.Identify potential vulnerabilities in system components based on the six STRIDE threat categories.Implement appropriate security controls to mitigate specific threat types.
PASTAExcellent for aligning threat modelling with business objectives. Unlike other frameworks, PASTA integrates business context, making it a more holistic and adaptable choice for organisations.
Conduct risk-centric threat modelling exercises aligned with business objectives.Prioritise threats based on their potential impact and risk level to the organisation.Build a flexible methodology that can be adapted to different organisational contexts.

In general, all these frameworks significantly aid in reducing risks in organisations by:

  • Enhancing threat awareness and identifying vulnerabilities
  • Prioritising risk mitigation efforts and optimising security controls
  • Continuous improvement and adaptation to evolving threats

All four frameworks have their unique strengths and applications in threat modelling. Leveraging these frameworks in real-world scenarios can significantly enhance an organisation’s ability to identify and mitigate risks, thereby reducing the overall risk landscape and improving resilience against potential threats.

Now that you have completed this room, you may proceed to Atomic Red Team and CALDERA (coming soon!) rooms to practice emulating threats!

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