Best Practices of Targeted Intrusion Remediation: Interview with Mandiant’s Jim Aldridge

Jim Aldridge Jim Aldridge of cyber security firm Mandiant helps organizations investigate and respond to security incidents. His areas of expertise include security incident response, penetration testing, security strategy, as well as secure systems and network design. Jim has significant experience working with the defense industrial base, technology, and industrial products sectors. In the Summer 2012 Jim spoke at Black Hat USA. Privacy PC asked Jim several questions regarding his presentation: “Targeted Intrusion Remediation: Lessons from the Front Lines”.

– Jim, in Mandiant experience, what proportions of security budgets are allocated to preventing attacks, detecting and remediating them?

– There are several factors that can determine how much an organization allocates to security – from the size of the company, to the perceived value of their assets. What’s true for all is allocating resources toward security to detect and stop an attack is significantly less expensive before an intrusion then after, when valuable IP has already been stolen.

– Are most organizations able to plan the remediation correctly and perform it quickly? Overall, how are organizations successful in remediation nowadays?

– Organizations are successful in remediation when they use an appropriate approach for their particular situation. Success doesn’t necessarily mean never having another intrusion but rather removing today’s attacker and implementing measures to respond more quickly and effectively the next time it happens.

– Seems like failing with a single step in your plan may kill all other efforts. What happens if an organization is not able to perform one step like disconnecting systems from the Internet?

Constituents of a remediation event

Constituents of a remediation event

– Remediation approaches are not “one size fits all”. I have worked with many organizations that successfully remediated without disconnecting from the Internet. The key is tailoring the approach to the situation. Good visibility into the attacker’s activities and understanding the scope of compromise provide crucial inputs to effective decision making. For example, if the attacker is very interested in the environment, and is currently active, disconnecting from the Internet will likely be more important. If an organization cannot fully disconnect, it may be possible to isolate certain networks where compromised systems reside.

I also advise building some redundancy into the plan, such that it doesn’t fail catastrophically if one step is not executed correctly.

– To quickly detect indicators of compromise, organizations should know what is normal in their environment and flows and what is abnormal. How often do they know it?

– The size and complexity of modern IT operations makes this area challenging. Some organizations have an understanding of “abnormal” for specific parts of their operations – e.g. abnormal traffic originating from specific servers that are highly monitored.

Is a user visiting a webpage that belongs to a local newspaper an indication of compromise? I’ve seen backdoors that obtain their instructions from the attacker by doing exactly that. Without the right intelligence, i.e. that a particular website is part of an attacker’s command and control infrastructure, how would you identify that?

Experience is crucial, as it enables one to spend time looking into truly suspicious conditions, ignoring red herrings.

– What are the best ways to quickly detect intrusions?

– The most effective incident response teams have knowledgeable, motivated people that are passionate about computer security hunting for intruders in the network. These people should be equipped with tools that provide them the ability to quickly ask questions about the environment. What systems out there have artifacts A, B and C? What systems resolved the domain name abc.123.com on January 8, 2013 between 05:00 and 08:00 UTC? The more quickly they get answers, and the more of the environment the queries cover, the better. Our Mandiant Intelligent Response (MIR) tool is something that we have developed over the years to help such teams solve exactly this problem.

– Your method of remediation suggests typically 4 to 8 weeks of planning and 1-2 days of executing. But what do you observe in reality with organizations which do not use your method? How do they organize their time and how long does it take them to remediate?

– It depends on several factors. One is the size of the organization. A company with 135,000 systems on six continents will require more time to prepare than a small company with one office. Another is an organization’s willingness to support solving the problem.

An organization will ideally be ready to contain and eradicate the threat at the same time they understand the scope of the compromise. Organizations must determine what systems are infected with malware and how the attacker is accessing the network to develop an effective containment strategy. Proceeding with an incomplete understanding of the intrusion often means attackers retain access to an environment.

One to two days is typically the maximum amount of time organizations can feasibly be essentially disconnected from the Internet. With appropriate preparation, that is usually enough time to perform key tasks like replacing the infected systems and changing passwords, even in large, global companies.

Read next: Interview with Jim Aldridge on Targeted Intrusion Remediation. Part 2

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