One of the most common methods of deploying systems is with images. If you’re planning on taking the Security+ exam, you should have a basic understanding of the overall process of capturing and deploying images.
For example, can you answer this question?
Q. Network administrators identified what appears to be malicious traffic coming from an internal computer, but only when no one is logged on to the computer. You suspect the system is infected with malware. It periodically runs an application that attempts to connect to web sites over port 80 with Telnet. After comparing the computer with a list of services from the standard image, you verify this application is very likely the problem. What process allowed you to make this determination?
A. Banner grabbing
B. Hardening
C. Whitelisting
D. Baselining
More, do you know why the correct answer is correct and the incorrect answers are incorrect? The answer and explanation is available at the end of this post.
Deploying Images for Baselines
An image is a snapshot of a single system that administrators deploy to multiple other systems. Imaging has become an important practice for many organizations because it streamlines deployments while also ensuring they are deployed in a secure manner. The following figure and the following text identify the overall process of capturing and deploying an image:
Capturing and deploying images
- Administrators start with a blank source system. They install and configure the operating system, install and configure any desired applications, and modify security settings. Administrators perform extensive testing to ensure the system works as desired and that it is secure before going to the next step.
- Next, administrators capture the image. Symantec Ghost is a popular imaging application, and Windows Server 2012 includes free tools many organizations use to capture and deploy images. The captured image is simply a file that can be stored on a server or copied to external media, such as a DVD or external USB drive.
- In step 3, administrators deploy the image to multiple systems. When used within a network, administrators can deploy the same image to dozens of systems during an initial deployment, or to just a single system to rebuild it. The image installs the same configuration on the target systems as the original source system created in step 1.
Administrators will often take a significant amount of time to configure and test the source system. They follow the same hardening practices and often use security and configuration baselines. If they’re deploying the image to just a few systems such as in a classroom setting, they may create the image in just a few hours. However, if they’re deploying it to thousands of systems within an organization, they may take weeks or months to create and test the image. Once they’ve created the image, they can deploy it relatively quickly with very little administrative effort.
Imaging provides two important benefits:
- Secure starting point. The image includes mandated security configurations for the system. Personnel who deploy the system don’t need to remember or follow extensive checklists to ensure that new systems are set up with all the detailed configuration and security settings. The deployed image retains all the settings of the original image. Administrators will still configure some settings, such as the computer name, after deploying the image.
- Reduced costs. Deploying imaged systems reduces the overall maintenance costs and improves reliability. Support personnel don’t need to learn several different end-user system environments to assist end users. Instead, they learn just one. When troubleshooting, support personnel spend their time focused on helping the end user rather than trying to learn the system configuration. Managers understand this as reducing the total cost of ownership (TCO) for systems.
The 601 Version of the Study Guide
The CompTIA Security+: Get Certified Get Ahead: SY0-601 Study GuideEach of the eleven chapters presents topics in an easy to understand manner and includes real-world examples of security principles in action.
You’ll understand the important and relevant security topics for the Security+ exam, without being overloaded with unnecessary details. Additionally, each chapter includes a comprehensive review section to help you focus on what’s important.
Over 300 realistic practice test questions with in-depth explanations will help you test your comprehension and readiness for the exam. The book includes:
- A 75 question pre-test
- A 75 question post-test
- Practice test questions at the end of every chapter.
Each practice test question includes a detailed explanation to help you understand the content and the reasoning behind the question. You’ll be ready to take and pass the exam the first time you take it.
If you plan to pursue any of the advanced security certifications, this guide will also help you lay a solid foundation of security knowledge. Learn this material, and you’ll be a step ahead for other exams. This SY0-601 study guide is for any IT or security professional interested in advancing in their field, and a must-read for anyone striving to master the basics of IT security.
Many virtualization tools include the ability to convert an image to a virtual system. In other words, once you create the image, you can deploy it to either a physical system or a virtual system. From a security perspective, there is no difference how you deploy it. If you’ve locked down the image for deployment to a physical system, you’ve locked it down for deployment to a virtual system.
Imaging isn’t limited to only desktop computers. You can image any system, including servers. For example, consider an organization that maintains 50 database servers in a large data center. The organization can use imaging to deploy new servers or as part of its disaster recovery plan to restore failed servers. It is much quicker to deploy an image to rebuild a failed server than it is to rebuild a server from scratch. As long as administrators keep the images up to date, this also helps ensure the recovered server starts in a secure state.
Remember this
Standardized images include mandatory security configurations. This ensures systems start in a secure state and reduces overall costs. Administrators are able to identify anomalies by comparing settings, services, and applications in the image with settings, services, and applications on live computers.
Q. Network administrators identified what appears to be malicious traffic coming from an internal computer, but only when no one is logged on to the computer. You suspect the system is infected with malware. It periodically runs an application that attempts to connect to web sites over port 80 with Telnet. After comparing the computer with a list of services from the standard image, you verify this application is very likely the problem. What process allowed you to make this determination?
A. Banner grabbing
B. Hardening
C. Whitelisting
D. Baselining
Answer is D. The standard image is the baseline and by comparing the list of services in the baseline with the services running on the suspect computer, you can identify unauthorized services. In this scenario, Telnet must not be in the baseline, but it is running on the suspect computer.
It’s possible an attacker has hijacked the computer to perform banner-grabbing attacks against external web sites, but banner grabbing doesn’t verify the problem on the computer.
Hardening makes a computer more secure than the default configuration, but it is done before creating a baseline.
Whitelisting identifies authorized applications and prevents unauthorized applications from running.
