Detection Engineering and Security Operations
Detection and Correlation Rule Development
We write detection and correlation rules that identify real attacker behavior. Each rule is tested against that behavior and tuned to reduce false alerts.
What it is
A detection rule is logic that turns specific attacker behavior in your logs into an alert. A correlation rule links multiple events in time and context. A good rule is based on behavior that is hard to change, not on a single IP address or file hash. Rules are kept in version control and retested with every change.
Scope
- Identifying rule needs from threat scenarios and MITRE ATT&CK techniques
- Writing rules in SIEM and EDR query languages, and in Sigma format where applicable
- Testing each rule by reproducing the same behavior in a controlled way
- Tuning and exception definitions based on normal behavior in your environment
- Analyst guide for each rule: purpose, likely false alerts, and first steps
The need
When organizations need it
- When the product's built-in rules generate so many false alerts that analysts miss real ones.
- When a new attack campaign targeting your sector is announced and you do not know if you have a rule for it.
- When the rule set has not been reviewed for years and it is unclear what each rule detects.
Method
How we work
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Need
We determine which behaviors require a rule from threat scenarios and current coverage gaps.
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Writing
We write the rule in your product's query language and document its logic and assumptions.
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Testing
We reproduce the behavior in a controlled test environment and show that the rule triggers. We run it on historical data to measure false alerts.
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Tuning and handover
We add exceptions and hand over the rule to your team with its analyst guide.
Outcome
What you have at the end
You have a rule set where every rule is tested, documented, and kept under version control. Analysts find instructions for each alert alongside the rule.
Frequently asked questions
Aren't the product's built-in rules sufficient?
Built-in rules are written for generic environments and do not know what is normal in yours. If left untuned, they often generate too many alerts or miss critical behavior.
In what format are the rules delivered?
Rules are delivered in the language of your SIEM or EDR product. Where applicable, they are also provided in Sigma format.
Do rules become outdated over time?
As your environment and attacker methods change, rules require review. Since test scenarios are delivered, your team can retest each rule.
Detection Engineering and Security Operations
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