# Source: https://docs.datadoghq.com/security/cloud_siem/detect_and_monitor/custom_detection_rules/sequence.md

---
title: Sequence
description: Learn about how the sequence detection method works.
breadcrumbs: >-
  Docs > Datadog Security > Cloud SIEM > Detect and Monitor > Custom Detection
  Rules > Sequence
---

# Sequence

## Overview{% #overview %}

The sequence method enables you to detect multi-stage attacks by identifying ordered patterns of related events, such as initial access, privilege escalation, and data exfiltration.

You can define a sequence of steps that must occur within a defined time frame and across related entities, such as a user, host, or IP address. Each sequence can combine conditions from multiple logs or signals to identify coordinated activity that might be missed by individual rules.

{% image
   source="https://datadog-docs.imgix.net/images/security/security_monitoring/detection_rules/sequence/preview.b08dc1a863ba7123da050cd7b70f2ff6.png?auto=format"
   alt="Sequence editor page showing a preview of the steps" /%}

See [Create Rule](https://docs.datadoghq.com/security/cloud_siem/detect_and_monitor/custom_detection_rules/create_rule/real_time_rule?tab=sequence) for instructions on how to configure a sequence rule.

## How the sequence method works{% #how-the-sequence-method-works %}

### Detection logic{% #detection-logic %}

{% image
   source="https://datadog-docs.imgix.net/images/security/security_monitoring/detection_rules/sequence/steps.68de2bdd5a0be2e0b5c3664c0df46f90.png?auto=format"
   alt="Sequence editor page showing three steps" /%}

Sequence detection evaluates a defined series of steps that represent distinct stages of suspicious behavior. Each step corresponds to:

- A condition such as a threshold on a log query or a signal match
- Transitions that define the order and time constraints between steps

The rule is triggered when all steps occur in the specified order and within the configured time windows.

### Linking entities{% #linking-entities %}

{% image
   source="https://datadog-docs.imgix.net/images/security/security_monitoring/detection_rules/sequence/linked_entities.772b680b2a1f4acbace10ab4787920f8.png?auto=format"
   alt="Sequence editor page showing a step with the group by field highlighted" /%}

The sequence of steps can be correlated across users, accounts, IP addresses, and other fields to automatically track linked entities through `group by` fields. This allows you to follow an attacker's path across different identities and systems.

### Evaluation window{% #evaluation-window %}

{% image
   source="https://datadog-docs.imgix.net/images/security/security_monitoring/detection_rules/sequence/evaluation_window.c59d3ccf054fb52b343ad070149ac75b.png?auto=format"
   alt="Sequence editor page showing the evaluation window highlighted" /%}

Each transition between steps has a configurable evaluation window that determines how long the rule waits for the next step to occur. For example, a rule might trigger when `user login from an unusual location` is followed within 20 minutes by a `privilege escalation`, where the user might have gone from a standard role to an admin role.

## Configuration options{% #configuration-options %}

When you [create a sequence detection rule](https://docs.datadoghq.com/security/cloud_siem/detect_and_monitor/custom_detection_rules/create_rule/real_time_rule?tab=sequence), you can configure these options:

| Setting           | Description                                                                   | Impact                                                                    |
| ----------------- | ----------------------------------------------------------------------------- | ------------------------------------------------------------------------- |
| Data type         | Specify whether each query evaluates logs, signals, or rules.                 | Defines data sources for detection.                                       |
| Steps             | Define each detection condition, including query and threshold.               | Determines which behaviors are monitored.                                 |
| Step transitions  | Define the order and time relationship between steps.                         | Controls when a sequence qualifies for a signal.                          |
| Evaluation window | After a step has occurred, the time (in seconds) to wait for the next step.   | Larger windows increase detection coverage, but may result in more noise. |
| Group by fields   | Fields used to link activity across steps (for example, `@usr.email`, `@ip`). | Determines how entities are correlated across queries.                    |

## Limits{% #limits %}

- Sequence detection supports up to 10 steps per rule and a total evaluation window of 24 hours.
- Steps must be in a linear sequence.

## Further reading{% #further-reading %}

- [Datadog Cloud SIEM: Driving innovation in security operations](https://www.datadoghq.com/blog/cloud-siem-enterprise-security)