The most powerful feature of Sigma is that it was designed for compatibility with whatever search and detection tools you’re already using. When you write detection rules with Sigma, you can better organize your rules and share those rules with colleagues and threat intel communities. Sigma provides the language necessary to describe detection logic and include metadata that’s helpful for investigating alerts generated from your rules. You can use Sigma to write rules for detecting threats in countless log types: proxy logs, Windows events, application logs, firewall logs, cloud events, Linux audit logs, and many more. The Sigma syntax provides a simple and powerful framework for expressing detection logic for diverse logs. Sigma is the open standard signature format for logs. So far, analysts have depended on Snort and Suricata signatures for network traffic and YARA signatures for files. That’s where popular open rule standards become valuable. You also need to write rules that are compatible with whatever search and detection mechanisms are available to you. You need to write rules that are specific enough so that they don’t create a lot of false positives but broad enough that they are resilient and don’t require constant updates. The alerts these tools generate are critical for identifying incidents. Detection engineering is all about the craft of expressing what you want to detect in ways that are compatible with these detection mechanisms so that they can dig through evidence and find evil. No matter the tool, they generally allow you to describe what you want to detect in a structured, specific way. Sigma is meant to be an open standard in which such detection mechanisms can be defined, shared and collected in order to improve the detection capabilities for everyone.Those tools come in several forms and include intrusion detection systems (IDS), log aggregators, antivirus engines, and a whole lot of fancy terms that basically mean math. Others provide excellent analyses, include IOCs and YARA rules to detect the malicious files and network connections, but have no way to describe a specific or generic detection method in log events. Some of their searches and correlations are great and very useful but they lack a standardized format in which they can share their work with others. People start working on their own, processing numerous white papers, blog posts and log analysis guidelines, extracting the necessary information and build their own searches and dashboard. Today, everyone collects log data for analysis. Provide Sigma signatures for malicious behaviour in your own application.Share the signature in threat intel communities - e.g.Share the signature in the appendix of your analysis along with IOCs and YARA rules.Write your SIEM searches in Sigma to avoid a vendor lock-in.Describe your detection method in Sigma to make it shareable. Sigma is for log files what Snort is for network traffic and YARA is for files. The main purpose of this project is to provide a structured form in which researchers or analysts can describe their once developed detection methods and make them shareable with others. The rule format is very flexible, easy to write and applicable to any type of log file. Sigma is a generic and open signature format that allows you to describe relevant log events in a straightforward manner. Generic Signature Format for SIEM Systems What is Sigma
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