Mastering Purple Teaming: Overcoming APTs with Katie Chuzie and Jesse Zhang

Table of Contents:

1. Introduction
2. What is Purple Teaming?
3. Implementing Purple Teaming at Microsoft
4. The Connection Between Purple Teaming and APT Emulation
5. The Role of Command and Control (C2) Infrastructure in APT Emulation
6. The Tech Stack Used in Copycat
7. Example of APT Emulation: Turla Dark Neuron Campaign
8. Example of APT Emulation: WinNTI Backdoor Campaign
9. Example of APT Emulation: Canon Campaign with Email Communication
10. Example of APT Emulation: Fin7 Grand Crab Campaign
11. Copycat Tool Features and Demos
12. Comparing Copycat to Other Frameworks
13. Future Plans and Potential Limitations
14. Conclusion

Introduction

In the ever-evolving world of cybersecurity, it is essential to stay one step ahead of malicious actors. A crucial aspect of this proactive approach is APT (Advanced Persistent Threat) emulation, where organizations simulate real-world attack scenarios to enhance their defensive strategies. Purple teaming, a methodology that brings together both offensive (red team) and defensive (Blue team) elements, plays a significant role in APT emulation. At Microsoft, purple teaming is practiced extensively to improve security measures. This article will explore the concept of purple teaming, its implementation at Microsoft, the connection between purple teaming and APT emulation, and how a tool called Copycat helps achieve APT emulation goals.

What is Purple Teaming?

Purple teaming is a collaborative methodology where red and blue teams work together to enhance the overall effectiveness of an organization's cybersecurity defenses. The red team, acting as the attacker, aims to exploit vulnerabilities and simulate real-world attacks. The blue team, acting as the defender, monitors and detects these attacks, striving to improve protective measures. By sharing knowledge and insights, both teams can learn from each other, identify weaknesses, and strengthen defensive strategies. This methodology fosters a proactive and holistic approach to cybersecurity, combining offensive and defensive capabilities for continuous improvement.

Implementing Purple Teaming at Microsoft

At Microsoft, purple teaming is an integral part of the cybersecurity framework. Through collaborative efforts, the red and blue teams work together, enhancing security measures. These teams continuously engage in purple teaming exercises, where the red team launches simulated attacks against test environments created explicitly for this purpose. The goal is to analyze detection effectiveness and evasion tactics. The blue team, on the other HAND, monitors and assesses the attack activity, aiming to detect and prevent any compromises. By sharing knowledge and insights, both teams can iterate, improve detection capabilities, and enhance defensive measures.

The Connection Between Purple Teaming and APT Emulation

APT emulation is a critical component of a proactive cybersecurity strategy. It involves simulating real-world threats by emulating the tactics, techniques, and procedures (TTPs) used by advanced persistent threat groups. Purple teaming plays a crucial role in the APT emulation process as it allows organizations to test their defensive capabilities against realistic attack scenarios. By working collaboratively, red and blue teams can identify vulnerabilities, assess the effectiveness of defensive measures, and improve incident response practices. This synergy between purple teaming and APT emulation empowers organizations to better protect their assets and mitigate potential risks.

The Role of Command and Control (C2) Infrastructure in APT Emulation

Central to APT emulation is the command and control (C2) infrastructure, which acts as the communication Channel between the attackers and the compromised systems (zombies). In the Context of APT emulation, C2 infrastructure is used to execute and control various activities performed by the emulated adversary. Copycat, a tool developed by Microsoft, incorporates a built-in C2 infrastructure to enable precise control over emulated APT campaigns. The C2 infrastructure allows for the deployment of binaries specific to each APT group and facilitates the execution of commands required for a particular APT profile. This seamless integration enhances the fidelity of APT emulation and enables a more comprehensive assessment of defensive measures.

The Tech Stack Used in Copycat

Copycat, the APT emulation tool developed by Microsoft, leverages the simplicity and versatility of the Go programming language. The choice of Go as the primary language for Copycat is driven by several key factors. First, Go runs on various platforms, allowing for effortless cross-compilation, which enables the tool to be deployed on multiple systems, including Raspberry Pi devices. This flexibility is advantageous for scenarios where covert deployment is desired. Second, Go boasts a concise and intuitive syntax, making it straightforward for developers to write and maintain code. Additionally, Go offers outstanding performance, ensuring that Copycat can execute operations efficiently. By utilizing Go for the tech stack, Copycat achieves a robust and adaptable framework for APT emulation.

Example of APT Emulation: Turla Dark Neuron Campaign

The Turla Dark Neuron campaign serves as an example of APT emulation within Copycat. Turla is an APT group known for its sophisticated cyber espionage activities targeting various organizations and governments. By implementing the Turla Dark Neuron campaign in Copycat, defenders can gain insights into Turla's tactics, techniques, and procedures. This emulation involves the deployment of a malicious macro embedded in a Word document sent through a spear-phishing email. Copycat's execution includes decoding and executing the malicious payload, emulating Turla's evasion tactics. As part of the emulation, Copycat evades detection by introducing random STRING variables and breaking up the Base64 encoding. Through this APT emulation, defenders can assess their detection capabilities and identify potential gaps in their defense against the Turla Dark Neuron campaign.

Example of APT Emulation: WinNTI Backdoor Campaign

The WinNTI backdoor campaign is another example of APT emulation facilitated by Copycat. The WinNTI APT group is notable for its advanced techniques and tools, targeting organizations across various sectors. By emulating the WinNTI backdoor campaign, defenders can assess their resistance against this specific APT group's tactics. Copycat emulates the backdoor's functionality, which involves resolving Windows system calls, dropping files, and executing malicious payloads. The implementation of WinNTI's IOCs (Indicators of Compromise) enables defenders to evaluate their detection and response capabilities against this APT group. Emulating the WinNTI campaign within Copycat provides valuable insights into potential vulnerabilities and the effectiveness of defensive measures.

Example of APT Emulation: Canon Campaign with Email Communication

Email communication plays a significant role in many APT campaigns. Emulating such campaigns in Copycat allows defenders to test their detection and response capabilities against email-Based APT attacks. The Canon campaign, which utilizes POP3 and SMTP protocols for communication, is an example of APT emulation within Copycat. By implementing the Canon campaign, defenders can evaluate their ability to detect and respond to email-based APT scenarios. Copycat emulates the POP3 and SMTP communication, allowing for the identification of malicious commands and data exfiltration techniques. The implementation of the Canon campaign within Copycat helps defenders validate the effectiveness of email-related security measures and refine their incident response strategies.

Example of APT Emulation: Fin7 Grand Crab Campaign

The Grand Crab campaign, attributed to the Fin7 APT group, is another illustrative example of APT emulation using Copycat. Fin7, also known as the Carbon Spider group, is notorious for its financially motivated cybercriminal activities targeting banks and institutions. By emulating the Grand Crab campaign, defenders can assess their defenses against Fin7's tactics. The Copycat implementation includes emulating the file names associated with the Grand Crab campaign, which are dropped on the victim machine. This APT emulation allows defenders to evaluate their detection and response capabilities, specifically focusing on file name-based detections. By analyzing the effectiveness of their defenses against the Grand Crab campaign, organizations can enhance their security posture and mitigate potential risks.

Copycat Tool Features and Demos

Copycat offers a diverse set of features designed to enhance APT emulation and empower defenders to evaluate their security measures effectively. Through the tool's command-line interface, defenders can issue commands to emulate specific APT profiles and campaigns. Copycat provides detailed information on the available profiles and campaigns, allowing users to understand the actions performed during an emulation. The tool supports various actions, including uploading files, executing commands, and interacting with emulated APT implants. Copycat also allows users to emulate communication channels commonly used by APT groups, such as email protocols POP3 and SMTP. By demonstrating different scenarios and showcasing Copycat's functionality, we have illustrated the tool's efficacy in enhancing APT emulation and facilitating informed defense strategies.

Comparing Copycat to Other Frameworks

Copycat distinguishes itself from other APT emulation frameworks by focusing on precision and capturing real-world attack techniques. Unlike some frameworks that attempt to emulate attacks in a fictional setting, Copycat draws inspiration from existing APT groups and their well-documented tactics. The tool leverages real IOCs and implements specific APT group profiles and campaigns to replicate authentic attack scenarios. This approach allows defenders to assess their defenses against actual threats and fine-tune their security measures accordingly. Copycat's versatility, Simplified tech stack involving the Go programming language, and emphasis on real-world APT emulation set it apart from other frameworks in the cybersecurity landscape.

Future Plans and Potential Limitations

Looking ahead, the development and improvement of Copycat will Continue, aiming to provide even more comprehensive APT emulation capabilities. Microsoft acknowledges the potential benefits of making this tool widely accessible, especially for organizations seeking to enhance their cybersecurity resilience. However, due to the sensitivity of APT emulation and concerns regarding misuse, authorizations and further considerations are required before public release. Microsoft is actively exploring options to enable organizations to utilize Copycat or similar tools to evaluate their security posture effectively. Transparency, accountability, and responsible use will guide the future plans for Copycat, ensuring that it serves as a valuable asset in the fight against cyber threats.

Conclusion

In the rapidly evolving landscape of cybersecurity, APT emulation and purple teaming play crucial roles in strengthening defenses against sophisticated attacks. By bringing together red and blue teams, organizations can assess the effectiveness of their security measures, detect vulnerabilities, and refine incident response strategies. Copycat, a tool developed by Microsoft, enables precise APT emulation by implementing real IOCs and specific APT group profiles and campaigns. Through examples of APT emulation, such as the Turla Dark Neuron, WinNTI, Canon, and Grand Crab campaigns, the power and versatility of Copycat have been demonstrated. While future plans for widespread accessibility are being explored, responsible use and continuous improvement will guide the tool's evolution. By embracing APT emulation and purple teaming methodologies, organizations can bolster their defenses and proactively safeguard their critical assets against emerging cyber threats.

Highlights:

• Purple teaming combines offensive (red team) and defensive (blue team) elements for enhanced cybersecurity defenses.
• Microsoft practices purple teaming extensively to improve security measures.
• APT emulation involves simulating real-world attack scenarios to assess defensive capabilities.
• Copycat is a tool developed by Microsoft for APT emulation, utilizing a built-in C2 infrastructure and various APT profiles and campaigns.
• Examples of APT emulation include Turla Dark Neuron, WinNTI, Canon, and Grand Crab campaigns.
• Copycat leverages the Go programming language for its simplicity, versatility, and performance.
• Comparisons between Copycat and other APT emulation frameworks demonstrate its focus on real-world attack techniques.
• Future plans for Copycat involve further exploration of authorizations and responsible use among organizations.
• APT emulation and purple teaming are critical in strengthening cybersecurity defenses and mitigating emerging threats.