Recently, one of the largest wireless carriers in North America revealed that hackers compromised a database of its customer information through unauthorized use of an API and acquired the personal details of millions of individuals, including names, addresses, phone numbers, and account numbers. Once identified, the company halted the malicious activity. However, investigations indicated that the data breach likely occurred months prior to being detected.
With the ever-increasing volume of data that organizations store in the cloud, malicious threats to their business sensitive data and resources will continue to grow alongside their online activity. Adversaries, also known as attackers, continue to use a variety of techniques to breach an organization’s security and compromise their systems, which can cause significant financial losses or damage to reputation or have legal consequences for the affected organization. To mitigate the damage caused, it is critically important for organizations to protect themselves by implementing various security measures and deploying tools to detect and respond to security threats. By being proactive, organizations can significantly reduce the risk of being victimized by cyber adversaries.
Amazon OpenSearch Service is a fully managed and scalable log analytics framework that you can use to ingest, store, and visualize data. You can use OpenSearch Service for a diverse set of data workloads including healthcare data, financial transactions information, application performance data, observability data, and much more. This managed service is valued for its ingest performance, scalability, low query latency, and its ability to analyze large datasets.
Security analytics with OpenSearch Service
Today, OpenSearch Service announces OpenSearch-powered security analytics, which includes features to monitor, analyze, and respond to potential security threats to your critical infrastructure. In this post, we discuss these new features and how to identify and remediate security threats.
Security analytics provide real-time visibility into potential threats across your infrastructure, enabling you to respond to security incidents quickly, thereby reducing the impact of any security breaches. It can also help you meet regulatory compliance requirements and improve your overall security posture.
Security analytics with OpenSearch is designed to gain visibility into a company’s infrastructure, monitor for anomalous activity, help detect potential security threats in real time, and trigger alerts to pre-configured destinations. You can monitor for malicious activity from your security event logs by continuously evaluating out-of-the-box security rules, and review auto generated security findings to aid your investigation. In addition, security analytics can generate automated alerts and send to a preconfigured destination of your choice such as Slack or email.
Security analytics is powered by the open-source OpenSearch project and deployed on OpenSearch Service with OpenSearch version 2.5 or higher. It includes the following key features:
- Out-of-the-box support for over 2,200 open-source Sigma security rules
- Support for log sources such as Windows, NetFlow, AWS CloudTrail, DNS, AD/LDAP, and more
- Detectors that auto generate findings based on the Sigma rules
- Automated alerts sent to preconfigured destinations
- A rules editor to create new custom rules or modify existing rules
- Visualizations to summarize findings and alerts trends
Sigma is a generic signature format, expressed using YAML (yet another markup language), to describe significant events that occur in your logs in a simple and straightforward way. The format is portable across different SIEM implementations and fosters a community of threat hunters, so that you don’t have to reinvent the wheel if you change your SIEM implementation.
An example of a simple rule to detect the run of C:WindowsSystem32rundll32.exe, one of the most commonly used methods for launching malicious code on a Windows platform, could be the following YAML configuration:
After you import this rule into the security analytics rules repository and enable it with your detector, it auto generates a security finding when the preceding condition matches an incoming event log.
Security analytics components and concepts
The security analytics offering includes a number of tools and features elemental to its operation. The major components that comprise the plugin are summarized in the following sections.
OpenSearch supports several types of logs and provides out-of-the-box mappings for each. The log type is specified during the creation of a detector and includes the ability to customize field mappings for that detector. For a log type selected in a detector, security analytics automatically enables a relevant set of rules that run at the configured interval.
Detectors are core components that you configure to identify a range of cybersecurity threats for a log type, across your data indexes. Detectors use custom rules and pre-packaged Sigma rules to evaluate events occurring in the system, automatically generating security findings from these events.
Rules, or threat detection rules, define the conditions applied to ingested log data to identify a security event. Security analytics provides prepackaged, open-source Sigma rules to detect common threats from your logs. Security analytics also supports importing, creating, and customizing rules to meet your requirements. Many rules are also mapped to an ever-growing knowledge base of adversary tactics and techniques maintained by the MITRE ATT&CK organization. You can take advantage of these options using either OpenSearch Dashboards or the APIs.
Findings are generated every time a detector matches a rule with a log event. Findings don’t necessarily point to imminent threats within the system, but they isolate an event of interest. Because they represent the result of a specific matched condition in a detector rule, findings include a unique combination of select rules, a log type, and a rule severity.
When defining a detector, you can specify one or more conditions that trigger an alert. When an event triggers an alert, the system sends a notification to a preferred channel, such as Slack or email. The alert can be triggered when the detector matches one or multiple rules. You can also create a notification message with a customized subject line and message body.
Taking the tool for a test drive
With an understanding of these fundamental concepts, let’s navigate to the security analytics interface in OpenSearch Dashboards. Security analytics also provides a robust set of configuration APIs.
After you have logged in to OpenSearch Dashboards and navigate to the security analytics overview page, you’re presented with the current state of the detectors you are monitoring. You can see a summary view comprised of multiple visualizations. The following chart, for example, shows the findings and alerts trend for various log types over a given period of time.
As you scroll down on the summary page, you can review your most recent findings and alerts.
Additionally, you can see a distribution of the most frequently triggered rules across all the active detectors. This can help you detect and investigate different types of malicious activities across log types.
Finally, you can view the status of configured detectors. From this panel, you can also navigate to the create detector workflow.
Creating a detector
In the previous section, we reviewed the overview page. Now, let’s walkthrough the create detector workflow. One of the best things about security analytics are the prepackaged rules. You don’t have to write your own. You can use the prepackaged rules to get up and running quickly! In the following example, we show you how to create a detector with prepackaged rules for your Windows logs.
- In the Dashboards navigation pane, under Security Analytics, choose Detectors.
- Choose Create Detector to create a new detector.
- First, give it a name and a data source to query. The data source can be a pattern or specific index.
- When you select a Log type, all matching rules are automatically loaded and enabled by default. In this example, we select Windows logs to help narrow the set of rules applied to this detector. As an optional step, you can choose to selectively enable or disable one or more rules. See an example rules selection panel below.
- Specify a schedule to run the rules and select Next.
- Configure any necessary field mappings per your rule.
You have two field mapping sections to optionally review. Default mapped fields provide pre-configured field mappings for the specific log type and enabled rules; you can skip this section unless you need to change the mappings. Additional mappings can be configured in the Pending field mappings section.
- First, give it a name and a data source to query. The data source can be a pattern or specific index.
- Configure the alerts.
The final step of setting up a detector is to configure the alerts and review your configuration. Note that each detector can generate multiple findings or alerts, and you have the option to customize the alert destination based on a rule match criterion such as severity, tags etc. In this example, we show you how to match a single rule that monitors a password dump to a host file system (QuarksPwDumps Dump File) and send the alert to a destination of your choice.
- First, define the name of the alert.
- Set up the criticality based on configurations in the rule and select the tags.
- Give the alert a severity and select a channel.
If you need to create a new channel, there is a breadcrumb that sends you to the Notifications feature. You can create additional channels needed.
- Review the configuration and Create the detector. Once the detector is active, any time a rule is matched for your incoming logs, it will automatically generate a security finding and alert (if configured).
Configuring custom rules
One of the key capabilities of security analytics is defining custom rules and being able to import rules created by others such as a community of threat hunters. As mentioned before, security analytics includes over 2200 rules out of the box. In some cases, you may want to create your own rules. If you navigate to the Rules page, you have the option to create your own rule.
The rules editor allows you to provide a custom rule that it will automatically validate. Once created, the rule is included in the rules library, helping you to customize your threat hunting needs.
Many organizations struggle with the high cost of commercial alternatives and are required to duplicate their data across multiple systems that generate specific insights. OpenSearch Service security analytics provides an open-source alternative to businesses that seek to reduce the cost of their security products. There is no additional charge for security analytics, and you can customize it to meet the security requirements of your organization. With simple workflows and prepackaged security content, security analytics enables your security teams to detect potential threats quickly while providing the tools to help with security investigations.
To get started, create or upgrade your existing Amazon OpenSearch Service domain to OpenSearch version 2.5. To learn more about security analytics, see documentation.
About the Authors
Kevin Fallis (@AWSCodeWarrior) is an Principal AWS Specialist Search Solutions Architect. His passion at AWS is to help customers leverage the correct mix of AWS services to achieve success for their business goals. His after-work activities include family, DIY projects, carpentry, playing drums, and all things music.
Jimish Shah is a Senior Product Manager at AWS with 15+ years of experience bringing products to market in log analytics, cybersecurity, and IP video streaming. He’s passionate about launching products that offer delightful customer experiences, and solve complex customer problems. In his free time, he enjoys exploring cafes, hiking, and taking long walks