Understanding Actor Characteristics in Threat Modeling: Capabilities and Risks

In cybersecurity, understanding actor characteristics is essential to performing comprehensive threat modeling activities. Actor characteristics refer to the traits, capabilities, and resources that adversaries may possess, influencing the nature and impact of potential attacks. Within the CompTIA SecurityX Governance, Risk, and Compliance (GRC) framework, accurately assessing these characteristics strengthens threat modeling, helping organizations protect critical assets and mitigate potential risks.

This article focuses on the capabilities of cyber actors, with a particular focus on supply chain access, vulnerability creation, knowledge, and exploit creation, as they relate to threat modeling and security posture.

Why Actor Characteristics Matter in Threat Modeling

Understanding an adversary’s capabilities enables organizations to identify the most relevant threats and prioritize defenses accordingly. Each capability or characteristic of an actor informs the likelihood, impact, and method of attack, enabling organizations to make informed security decisions. By incorporating these characteristics into threat modeling, security teams can anticipate threats, design effective controls, and align with Governance, Risk, and Compliance objectives.

Key Capabilities of Cyber Actors

The capabilities of threat actors vary widely based on their resources, knowledge, and goals. Below are four primary capabilities that play a critical role in assessing threat risk in threat modeling:

1. Supply Chain Access
2. Vulnerability Creation
3. Knowledge and Expertise
4. Exploit Creation

1. Supply Chain Access: Evaluating Indirect Risks

Supply chain access is a significant capability that can allow an adversary to infiltrate multiple systems indirectly through trusted third parties or vendors. Threat actors with supply chain access can introduce risks throughout the vendor ecosystem, making them especially dangerous for organizations with extensive supplier relationships.

• Supply Chain Attacks: Threat actors leverage vulnerabilities in vendors’ or partners’ systems to access an organization’s network. Notable examples include the SolarWinds attack, where adversaries compromised a widely-used software provider to access numerous downstream clients.
• Risks of Trusted Access: Many vendors or suppliers have trusted access to internal systems. Adversaries with supply chain access can use this to bypass traditional security measures, making it essential to closely monitor and manage third-party risks.

Mitigation Strategies for Supply Chain Access

• Vendor Security Assessments: Regularly evaluate third-party security practices and verify that vendors comply with industry security standards.
• Zero Trust Principles: Adopt a zero-trust approach with vendors by limiting their access to only necessary resources and monitoring for any unusual activity.
• Network Segmentation: Segment networks to ensure that a compromised supplier or vendor does not have access to the entire organization’s resources, limiting potential damage.

2. Vulnerability Creation: Adversary Manipulation of Security Weaknesses

Vulnerability creation refers to an adversary’s ability to find or create new vulnerabilities in software, applications, or hardware. This capability is more common among sophisticated actors, such as nation-states or well-funded criminal organizations, who can manipulate the software or hardware supply chain to introduce weaknesses that they or others can exploit.

• Supply Chain Injection of Vulnerabilities: In some cases, threat actors can plant vulnerabilities within the software or hardware supply chain, allowing them to compromise end-user systems indirectly.
• Exploit Kits and Toolkits: Some actors develop or distribute exploit kits specifically designed to target newly discovered vulnerabilities, enabling other malicious actors to launch attacks.

Mitigation Strategies for Vulnerability Creation

• Software Composition Analysis (SCA): Use SCA tools to scan for known vulnerabilities in software components, ensuring that components with vulnerabilities are flagged and updated.
• Rigorous Code Reviews: Require comprehensive code reviews during the software development lifecycle to detect vulnerabilities introduced either accidentally or deliberately.
• Regular Patching and Updates: Continuously update software and patch vulnerabilities as they are discovered to prevent attackers from exploiting known weaknesses.

3. Knowledge and Expertise: Understanding Threat Actor Proficiency

Threat actors’ knowledge and expertise in specific domains (e.g., operating systems, encryption, web applications) determine the complexity and effectiveness of the attacks they can execute. This characteristic helps security teams understand the level of skill they are up against and prepare accordingly.

• Technical Skill Level: Highly skilled adversaries are capable of bypassing complex defenses, making them more likely to exploit advanced vulnerabilities or develop new attack methods.
• Domain-Specific Expertise: Some adversaries specialize in particular fields, such as cloud environments or industrial control systems (ICS). Such expertise enables them to craft targeted attacks in these areas.
• Research and Development: Nation-state actors or large cybercrime organizations often invest in research to understand potential new attack vectors, making them particularly dangerous.

Mitigation Strategies for Addressing Knowledge-Based Threats

• Behavioral Analytics and Threat Hunting: Use behavioral analytics and threat-hunting teams to identify sophisticated adversary tactics that standard defenses may miss.
• Incident Response (IR) Drills: Conduct incident response drills that simulate attacks from skilled adversaries, preparing the team for advanced threat scenarios.
• Threat Intelligence Integration: Subscribe to threat intelligence feeds that provide information on newly discovered TTPs (tactics, techniques, and procedures), keeping the security team informed of evolving threat actor methods.

4. Exploit Creation: Weaponizing Vulnerabilities

Exploit creation is a capability primarily associated with highly advanced actors who have the resources and expertise to develop tools that can exploit specific vulnerabilities. This skill allows adversaries to create or customize exploits to bypass security controls, which they may use themselves or distribute to other malicious actors.

• Zero-Day Exploits: Some actors are capable of discovering and weaponizing vulnerabilities that have not yet been publicly disclosed (zero-days). This gives them a significant advantage, as defenses are not yet aware of or equipped to handle these threats.
• Customized Malware Development: Many sophisticated actors develop customized malware to exploit known or new vulnerabilities, enabling precise, targeted attacks.
• Exploit Kits: Exploit kits are bundles of code that exploit common vulnerabilities, often available for purchase or trade on dark web marketplaces, making them accessible to a range of threat actors.

Mitigation Strategies for Exploit Creation

• Multi-Layered Defense (Defense in Depth): Implement multiple layers of security, including network segmentation, firewalls, and intrusion detection systems (IDS), to make it more challenging for exploit attempts to succeed.
• Application Control and Whitelisting: Restrict applications that can run on critical systems to pre-approved software, reducing the risk of exploit-based malware.
• Regular Vulnerability Assessments: Conduct regular vulnerability scans to detect and patch exploitable vulnerabilities quickly, minimizing the time window for attackers to create effective exploits.

Integrating Actor Characteristics into Threat Modeling for GRC

Incorporating actor characteristics into threat modeling strengthens the organization’s ability to defend against various adversaries while aligning with Governance, Risk, and Compliance (GRC) objectives:

1. Enhanced Risk Assessment: Understanding the capabilities of likely adversaries enables organizations to conduct more accurate risk assessments, helping prioritize high-impact threats.
2. Proactive Compliance: Compliance frameworks such as NIST, ISO, and PCI DSS require proactive threat detection and response. Integrating actor characteristics supports a thorough threat assessment, satisfying these compliance requirements.
3. Improved Security Governance: By analyzing actor characteristics, security teams can adopt a structured approach to defense, aligning security practices with organizational policies and risk tolerance.

Best Practices for Integrating Actor Characteristics into Security Operations

To maximize the benefits of understanding actor characteristics, organizations should follow these best practices:

1. Use Threat Intelligence Platforms (TIPs)
   • TIPs provide up-to-date insights into adversary capabilities, behaviors, and intentions, enabling organizations to continuously update their threat models based on new intelligence.
2. Conduct Red Team Exercises Focused on Actor Characteristics
   • Simulate attacks that mirror real-world actor capabilities, such as exploiting supply chain vulnerabilities or deploying zero-day exploits, to test defenses and identify gaps.
3. Develop Tailored Incident Response Plans
   • Tailor incident response plans to handle potential attacks from different adversary profiles, ensuring the organization is prepared for various threat scenarios.
4. Provide Regular Training and Scenario-Based Exercises
   • Educate employees and security teams on different threat actor capabilities, including common attack patterns and indicators of compromise, to improve detection and response.

Conclusion

Understanding actor characteristics in threat modeling allows organizations to anticipate, assess, and mitigate potential threats more effectively. By focusing on key capabilities such as supply chain access, vulnerability creation, knowledge, and exploit creation, organizations can align their defenses with GRC objectives, enhancing their security posture and resilience. Through structured threat modeling and proactive security measures, organizations can mitigate risk, prepare for emerging threats, and strengthen compliance with evolving security standards.

Frequently Asked Questions Related to Actor Characteristics in Threat Modeling