Tutorial / Cram Notes
ASR policies help organizations minimize the areas that malicious actors can target, reducing the risk of successful cyber-attacks. By carefully planning and implementing ASR policies, IT administrators can significantly enhance the security posture of their infrastructure.
Understanding Attack Surface Reduction Policies
An attack surface consists of the various points where an unauthorized user can try to enter data to or extract data from an environment. Microsoft 365 provides several built-in features to help reduce this attack surface, and ASR policies are tools that specifically limit the actions that can be taken by potentially malicious software.
Planning ASR Policies
The planning phase is critical. Organizations should:
- Identify critical assets and sensitive data.
- Assess current security posture and potential vulnerabilities.
- Define security requirements and compliance obligations.
- Involve stakeholders to ensure policy alignment with business operations.
Implementing ASR Policies
To implement ASR policies, you should follow these general steps:
- Determine Baseline Security Settings: Review default security settings within Microsoft 365 and determine if they meet your organization’s needs. Consider using the Security Compliance Toolkit provided by Microsoft to assess these settings.
- Customize ASR Rules: Microsoft provides a set of ASR rules that can be tailored to the needs of each organization. These rules can be set to block, audit, or warn the actions that are considered risky.
- Deploy ASR Policies Environment-Wide: ASR policies should be applied consistently across the entire environment, including all endpoints.
- Test and Monitor: Before widespread deployment, it’s important to test the policies to ensure they do not interfere with legitimate business activities and monitor their performance.
- Review and Update Regularly: As threats evolve, so should ASR policies. Regular review and updates are necessary to ensure ongoing protection.
Examples of ASR Rules
Here are examples of some ASR rules that organizations can implement:
- Block executable content from email client and webmail: This rule prevents the execution of potentially malicious, executable files from email.
- Use advanced protection against ransomware: This involves turning on features like controlled folder access to prevent unauthorized changes to files.
- Block credential theft from the Windows local security authority subsystem: This helps in preventing attacks like Pass-the-Hash and Pass-the-Ticket which can lead to credential theft.
- Block JavaScript or VBScript from launching downloaded executable content: This applies to web browsers and email clients, blocking potentially dangerous scripts from launching executables.
Monitoring and Reporting
After ASR policies have been implemented, their activity should be continuously monitored. Microsoft 365 offers tools like the Microsoft 365 security center for monitoring the performance of ASR rules. It provides detailed reports and alerts, which help quickly identify and respond to potential threats.
Conclusion
Implementing attack surface reduction policies within Microsoft 365 environments is paramount to mitigating risks and enhancing security. A careful, informed process of planning, deploying, and managing ASR rules can help safeguard organizations against the rapidly evolving landscape of cyber threats. Remember, security is an ongoing process, and ASR policies should adapt as the organization’s needs, and the threat environment changes.
Practice Test with Explanation
True or False: Attack surface reduction (ASR) rules can only be applied to devices running Windows 10 Enterprise.
- A) True
- B) False
Answer: B) False
Explanation: ASR rules can be applied to devices running Windows 10 Pro, Enterprise, and Education editions.
Which tool can be used to implement attack surface reduction policies in Microsoft 365?
- A) Azure Active Directory
- B) Microsoft Defender for Endpoints
- C) System Center Configuration Manager
- D) Microsoft Intune
Answer: D) Microsoft Intune
Explanation: Microsoft Intune is used to manage and implement attack surface reduction policies in Microsoft 365 environments.
True or False: Attack surface reduction rules are designed to prevent actions that malware often abuses to compromise systems and networks.
- A) True
- B) False
Answer: A) True
Explanation: Attack surface reduction rules are indeed designed to prevent actions that are commonly used by malware to infiltrate and compromise systems.
Which of the following is NOT a valid attack surface reduction rule in Microsoft 365?
- A) Block executable content from email client and webmail
- B) Block all outbound connections to the Internet
- C) Block process creations originating from PSExec and WMI commands
- D) Use advanced protection against ransomware
Answer: B) Block all outbound connections to the Internet
Explanation: There is no ASR rule that blocks all outbound Internet connections, as this would severely limit legitimate network use.
True or False: You must use Group Policy to configure ASR rules if your devices are joined to an on-premises Active Directory domain.
- A) True
- B) False
Answer: B) False
Explanation: While Group Policy is one option for on-premises Active Directory domain-joined devices, ASR rules can also be configured via Microsoft Endpoint Manager (which includes Intune) and PowerShell scripts.
True or False: Attack surface reduction rules can be set to Audit Mode to assess the impact of the rule before fully enforcing it.
- A) True
- B) False
Answer: A) True
Explanation: ASR rules can indeed be set to Audit Mode, which allows administrators to see the impact and potential false positives before enforcing the rules in the environment.
Which PowerShell cmdlet is used to configure attack surface reduction rules?
- A) Set-MpPreference
- B) Set-ASRPolicy
- C) Set-AttackSurfaceReductionRule
- D) New-ASRRuleConfiguration
Answer: A) Set-MpPreference
Explanation: The “Set-MpPreference” cmdlet is used to configure ASR rules along with other Windows Defender Antivirus preferences.
True or False: Attack surface reduction rules support bulk actions for quickly applying rules to multiple devices at once.
- A) True
- B) False
Answer: A) True
Explanation: ASR rules can be bulk-applied to multiple devices through management tools like Microsoft Endpoint Manager (Intune).
In what scenarios might you use Microsoft Defender for Endpoint’s evaluation lab for attack surface reduction rules?
- A) To test new software installations
- B) To assess the impact of ASR rules on specific applications
- C) To review the deployed ASR rules only
- D) To perform an actual attack to check system resilience
Answer: B) To assess the impact of ASR rules on specific applications
Explanation: The evaluation lab feature within Microsoft Defender for Endpoint can be used to safely test the impact of ASR rules on specific applications in a controlled environment.
True or False: It’s recommended to enable all attack surface reduction rules at once to ensure maximum security.
- A) True
- B) False
Answer: B) False
Explanation: It is not recommended to enable all ASR rules at once, as they can affect legitimate business applications. It’s best to assess each rule’s impact in Audit Mode before full enforcement.
What is a primary objective of implementing attack surface reduction policies?
- A) To provide unrestricted access to resources
- B) To restrict user access to data
- C) To minimize the number of vulnerabilities that can be exploited
- D) To encrypt data at rest
Answer: C) To minimize the number of vulnerabilities that can be exploited
Explanation: The main goal of attack surface reduction policies is to reduce the attackable points (or vulnerabilities) within the environment, thus making it harder for attackers to exploit them.
True or False: Attack surface reduction rules can be applied to both applications and operating system behaviors.
- A) True
- B) False
Answer: A) True
Explanation: Attack surface reduction rules aim to mitigate activities that are typically used by malicious software, and this includes both applications and certain behaviors within the operating system.
Interview Questions
What is attack surface reduction?
Attack surface reduction is a security technique that is designed to reduce the potential attack surface of an IT environment by restricting access to certain types of applications, files, and settings.
What is Microsoft Intune?
Microsoft Intune is a cloud-based service that allows organizations to manage their devices and applications from a central location.
How can attack surface reduction policies be implemented using Microsoft Intune?
Attack surface reduction policies can be implemented using Microsoft Intune by creating policies that restrict access to certain types of applications, files, and settings.
What is Windows Defender ATP?
Windows Defender ATP is a cloud-based service that provides advanced threat protection for devices running Windows 10.
How can attack surface reduction policies be implemented using Windows Defender ATP?
Attack surface reduction policies can be implemented using Windows Defender ATP by configuring policy settings such as network protection or blocking certain types of applications.
How can organizations monitor non-compliance with attack surface reduction policies?
Organizations can monitor non-compliance with attack surface reduction policies using reports in Microsoft Intune or the Windows Defender Security Center.
What are some common attack surface reduction policies that can be enforced using Microsoft Intune?
Some common attack surface reduction policies that can be enforced using Microsoft Intune include restricting access to certain types of applications or settings, and controlling device driver installations.
What are some common attack surface reduction policies that can be enforced using Windows Defender ATP?
Some common attack surface reduction policies that can be enforced using Windows Defender ATP include network protection and blocking Office applications from creating child processes.
What is Windows Defender Antivirus?
Windows Defender Antivirus is a built-in antivirus solution that provides real-time protection against viruses, malware, and other threats.
How can Windows Defender Antivirus be configured to meet an organization’s specific needs?
Windows Defender Antivirus can be configured to meet an organization’s specific needs by adjusting the settings for features such as cloud-delivered protection, real-time protection, and automatic sample submission.
What is the benefit of implementing attack surface reduction policies?
Implementing attack surface reduction policies can help organizations limit the potential attack surface of their IT environment and reduce the risk of cyberattacks.
Can attack surface reduction policies be customized to meet an organization’s specific needs?
Yes, attack surface reduction policies can be customized to meet an organization’s specific needs by adjusting policy settings and choosing which devices the policies are enforced on.
What should organizations do if they identify non-compliance with attack surface reduction policies?
Organizations should take appropriate action to address non-compliance with attack surface reduction policies, such as updating the policies or re-assigning devices to different policies.
How can organizations ensure that their devices are protected against cyberattacks?
Organizations can ensure that their devices are protected against cyberattacks by implementing a combination of security measures, including attack surface reduction policies, antivirus software, and other protective measures.
How often should organizations review and update their attack surface reduction policies?
Organizations should review and update their attack surface reduction policies on a regular basis, depending on the specific needs of the organization and the current threat landscape.
Great blog post! Helped a lot with my MS-101 exam prep.
Could anyone explain how to configure Attack Surface Reduction (ASR) rules for Office apps?
I was confused about setting scoped policy targets. Any advice?
Can ASR cause false positives in a work environment?
Appreciate the blog post, very informative!
How do I manage exceptions in ASR policies?
Deploying ASR policies through MEM Intune is more streamlined. Any step-by-step guide available?
I faced issues with ASR and OneDrive sync. Anyone else?