Monday, November 29, 2021

How to defend against advanced attacks

This fall, we released Decoding NOBELIUM, a four-part video series that pulls back the curtain on the world of threat detection and showcases the incredible efforts and insights from defenders who responded to the most sophisticated nation-state attack in history. Since we first started sharing information on this extremely advanced threat actor group in December 2020, we have only continued to see an increase in nation-state activity.


In this blog, we’ll share some of the insights that we heard from leading cybersecurity experts while filming the Decoding NOBELIUM series that you can use to help your own organization better prepare for advanced attacks. This guidance is grounded in real-world examples and not only applies to defending against advanced adversaries but will also strengthen your security posture against more common threats like phishing, email compromise, ransomware, and more. Let’s dive in.


Defending against nation-state actors

Nation-state actors are persistent, well-funded, and exceptionally skilled at reconnaissance. In practice, this means they’re very good at finding the gaps in security—whether that be exploiting an identity with high-level access, a port into the network that is left open, or an app from a trusted software provider by injecting malicious code.


Start with a strong foundation—Zero Trust

While there are many individual things that can be done to protect your organization against these advanced adversaries, one of the most critical components is to ensure you have a robust Zero Trust strategy and are working on applying its guiding principles broadly. Zero Trust helps with both the prevention of and detection and response of a breach. In the case of the SolarWinds compromise, organizations that had applied micro-segmentation to their infrastructure were much more effective at limiting the damage of compromised software being inside the corporate firewall.


Advanced adversaries like NOBELIUM will exploit virtually any gap they can find—so a comprehensive deployment is critical. Organizations that embrace Zero Trust are more prepared for defending against sophisticated threats because their security foundations and baselines are stronger. Adopting Zero Trust requirements like verifying identities explicitly and enforcing least privileged access dramatically reduce the impact of breaches—and in some cases, even prevent it. For example, one of the ways NOBELIUM succeeded was by targeting and compromising highly privileged vendor accounts that lacked protections such as multifactor authentication (MFA), access policy restrictions, or device compliance. By enforcing conditional access policies for all users, organizations are significantly more resilient against account compromise.


And the Zero Trust principles around identity are really about ensuring you have strong identity, so you know who is accessing something, from what device or endpoint, and that it is strongly authenticated against what service and where. You have areas of risk because you're not able to get the strength of the identity or authentication as you want, so you have to limit or have conditional access so you can manage your risk proportional to the situation. So those principles a very important for customers to go fully embrace and modernize their identity infrastructure.” John Lambert, General Manager, Microsoft Security Threat Intelligence Center


To learn about Microsoft’s approach to Zero Trust by checking out the updated maturity model and architecture shared earlier this month. And for technical guidance and resources on implementing Zero Trust across your entire digital environment, check out the Zero Trust Guidance Center.


Focus on cyber-hygiene

While many nation-state attacks make headlines for sophisticated attack chains and zero-day vulnerabilities, these sophisticated actors prefer to use the lowest cost, highest impact tactics they can in order to accomplish their objectives. This means, more often than not, they’re using very common tactics, techniques, and procedures (TTPs)—such as remotely accessing systems with accounts not protected by MFA or taking advantage of known vulnerabilities on unpatched systems. We can’t understate how important it is to get the fundamentals right. According to our annual report, basic cyber-hygiene protects against 98% of attacks.


“It's too often that nation-states don't need advanced sophisticated tactics like we saw.” - Cristin Goodwin, General Manager, Microsoft Digital Security Unit


Fortunately, strong cyber-hygiene can dramatically increase the cost to attackers—making them more likely to move on or take riskier actions that are easier to detect.


Keeping up with patches on your operating system, your workstations, your middleware tier, your web applications, all of those things are really important to ensure that you're maintaining a base level of security because those are already known issues that hackers are going to exploit and specific things to that effect.“Dave Kennedy, CEO and Founder, TrustedSec and Binary Defense


Make sure you’re enabling MFA, applying least privilege access, keeping your software up to date, utilizing antimalware broadly, and implementing best practices like applying sensitivity labels and data loss prevention policies to protect your data. Read the report for our full list of recommendations based on what we’re seeing is most effective at defending against today’s threat landscape.


Protect your identities

“The attacks of the future, a lot of them are going to be identity based. Once I can authenticate into your environment, I don't need malware anymore.”Roberto, Principal Consultant and Lead Investigator, Microsoft Detection and Response Team


Increasingly, major security incidents start with just one compromised account—whether through phishing, password spraying, or purchasing paired user-names and passwords on the dark web. Once attackers get their foot inside the perimeter, they can more easily escalate their privileges or gather intelligence that helps them reach their objectives. Protecting identities is twofold: First, we need to make it harder to steal an identity; second, we need to make it easier to detect accounts that have been compromised.


Fortunately, there are some simple actions we can take to dramatically reduce the risk of compromised accounts. Enforcing MFA can prevent up to 99.9% of account compromise attacks. Blocking legacy authentication protocols like POP, SMTP, IMAP, and MAPI that can’t enforce MFA will also help drastically reduce your attack surface area. As you build out your program, make sure to prioritize privileged accounts, which are often the top target for attackers.


To help make it easier to detect a compromised user, Microsoft’s defenders recommend making sure you’re using user and entities behavioral analytics (UEBA). This allows your organization to build a baseline of how your users and devices behave, making it much easier to identify anomalous behavior.


“Identity is the number one entry in access point for the majority of all of these attacks, and if you can get a handle on identity first, then your journey towards being secure is going to be immensely faster and more efficient.”Elizabeth Stephens, Chief of Staff, Microsoft 365 Security


Check out the blog, Prevent and detect more identity-based attacks with Azure Active Directory, by my colleagues Kristina and Sarah for more information on how to protect your identities.


Use secure devices for critical tasks

Security experts recommend protecting privileged accounts in order to secure access to highly-sensitive data. However, that alone isn’t enough protection—for example, an adversary can attack a device directly. The shift to remote work has increased the adoption of accessible Remote Desktop Protocol (RDP), and there’s now an abundance of RDP ports and protocols publicly exposed to the internet for attackers to gain access using a brute force attack to compromise accounts. To add another layer of defense for your critical data, they strongly advise securing those originating devices.


If you [Remote] Desktop Protocol into a box, don't leave the session open when you leave. Close the session, 'cause then they can't just grab your session and start using your login.” – Joanne, Security Analyst, Microsoft DSR Security Operations Center HUNT Team


Joanne also recommends taking a few more steps to help protect your devices and most-sensitive data:

“…You want to use a secure networking device. You don't want to use your everyday workstation or everyday desktop to do administrative tasks on sensitive systems. You want to have a separate system…a System Administrator Workstation (SAW). You want to have some kind of SAW device to do your administrative tasks from.”Joanne, Security Analyst, Microsoft DSR Security Operations Center HUNT Team


Learn about how we use SAWs at Microsoft to protect our own environment. And to learn more about the requirements of SAWs and how to deploy the security controls to secure a workstation for sensitive users, check out our documentation.


Implement robust monitoring systems and build a baseline of your environment


“This incident showed the attackers will leverage very different parts of an environment, both in the cloud and on-prem, to achieve what they want.”Pete, Senior Software Engineer, Microsoft Threat Intelligence Center


Today’s environments offer plenty of places for attackers to hide in the shadows, so it’s become critical to identify attacker behavior more effectively. While prevention is critical, many organizations need to further strengthen their detection and response capabilities. To get started, ensure your security team has the right tools in place for an accurate and fast response. For example, today’s robust security analytics systems can help correlate seemingly individual events across multiple domains into a single view of an attacker's kill chain.


“In order to respond to an attack like NOBELIUM, with its scope and breadth and sophistication, you really need to have visibility into various entities across your entire digital state. So you need to have visibility into security data and events relating to users, endpoints, and infrastructure whether on-prem or in the cloud” – Sarah Fender, Partner Product Manager, Microsoft Azure Sentinel


There are quite a few different approaches and solutions out there to help your organization tackle this challenge. Our experts recommend taking a holistic, integrated approach to avoid fragmentation. Microsoft offers a solution that combines our cloud-based SIEM, Azure Sentinel, along with our XDR technologies, including Microsoft 365 Defender, to provide an automated approach to threat detection and response across the entire environment. Check out a Mechanics Video with Rob Lefferts to see how this combination can help organizations respond quickly to an attacker like NOBELIUM.


Plan your response and practice

And it’s not just about technology—organizations need a comprehensive incident response plan and a well-trained team at the ready. 

“Supply chain threats really reinforce how important it is to know what's in your environment and be able to manage it, and then critically have a backup plan. It's that it's not a matter of if, it's when. And you want to have responders that are well-practiced at these incidents and able to respond some things that help them in response.”John Lambert, General Manager, Microsoft Security Threat Intelligence Center


In a recent study, Microsoft conducted, 39% of CISOs report having little to no incident planning in place. The NOBELIUM attack really reinforced the importance of having a robust plan, team, and set of capabilities in place during a large-scale attack. We found that organizations that were prepared responded more quickly, limiting the damage and keeping the business running. Additionally, a 2021 Ponemon study, Cost of a Data Breach Report 2021, found that organizations without a meaningful incident response team and plan in place saw the cost of their breach go up by 55%.


Preparation should also extend beyond planning to include real-world practice and testing of your defenses. This will help ensure not only that your security team is prepared to execute the response plan effectively, but that plans are effective and any weaknesses are discovered and addressed before the real attack happens.


“Given some of our findings and some of our takeaways from this attack, investing in penetration testing, investing in putting together teams and practice[ing].” Ramin, Senior Malware Reverse Engineer, Microsoft Threat Intelligence Center


Check out our documentation on conducting pen testing in Microsoft Azure and running attack simulations in Microsoft 365 to begin tests in your own environment.


Additional resources and next steps

Microsoft is committed to helping organizations stay protected from cyberattacks, whether cybercriminal or nation-state by utilizing our leading threat intelligence and global team of dedicated cybersecurity defenders to combat global threats. Just two recent examples of Microsoft’s efforts to combat nation-state attacks include a September 2021 discovery and investigation of a NOBELIUM malware referred to as FoggyWeb and our May 2021 profiling of NOBELIUM’s early-stage toolset compromising EnvyScout, BoomBox, NativeZone, and VaporRage.

If you’re interested in learning more about how Microsoft defenders and industry partners respond to nation-state attacks, check out the full Decoding NOBELIUM series where you’ll gain insights and learn critical steps to improve your security posture against the next wave of attacks.

For more information on cyberattacks, whether cybercriminals or nation-state, check out the Microsoft Security Response Center.





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