Panther Analysis Tool

The panther_analysis_tool is an open source utility for testing, packaging, and deploying Panther detections from source code.
It's designed for developer-centric workflows such as managing your Panther analysis packs programmatically or within CI/CD pipelines.
For more information on tailoring detections with dynamic alert fields, see alert field overrides​
Installation
pip3 install panther_analysis_tool
File Organization
It's best practice to create a fork of Panther's open source analysis repository.
To get started, navigate to the locally checked out copy of your custom detections.
We recommend creating folders based on log/resource type, such as suricata_rules or aws_s3_policies. Use the open source Panther Analysis packs as a reference.
Each analysis consists of:
A Python file containing your detection/audit logic
A valid YAML or JSON specification file containing attributes of the detection. By convention, we give this file the same name as the Python file.
Writing Rules
Rules are Python functions to detect suspicious behaviors. Returning a value of True indicates suspicious activity, which triggers an alert.
First, write your rule and save it (in your folder of choice) as my_new_rule.py:
def rule(event):
  return 'prod' in event.get('hostName')
Then, create a specification file using the template below:
AnalysisType: rule
DedupPeriodMinutes: 60 # 1 hour
DisplayName: Example Rule to Check the Format of the Spec
Enabled: true
Filename: my_new_rule.py
RuleID: Type.Behavior.MoreContext
Severity: High
LogTypes:
  - LogType.GoesHere
Reports:
  ReportName (like CIS, MITRE ATT&CK):
    - The specific report section relevant to this rule
Tags:
  - Tags
  - Go
  - Here
Description: >
  This rule exists to validate the CLI workflows of the Panther CLI
Runbook: >
  First, find out who wrote this the spec format, then notify them with feedback.
Reference: https://www.a-clickable-link-to-more-info.com
When this rule is uploaded, each of the fields you would normally populate in the UI will be auto-filled.
Rule Specification Reference
A complete list of rule specification fields:
Field Name
Required
Description
Expected Value
AnalysisType
Yes
Indicates whether this analysis is a rule, policy, or global
rule
Enabled
Yes
Whether this rule is enabled
Boolean
FileName
Yes
The path (with file extension) to the python rule body
String
RuleID
Yes
The unique identifier of the rule
String
LogTypes
Yes
The list of logs to apply this rule to
List of strings
Severity
Yes
What severity this rule is
One of the following strings: Info, Low, Medium, High, or Critical
Description
No
A brief description of the rule
String
DisplayName
No
A friendly name to show in the UI and alerts. The RuleID will be displayed if this field is not set.
String
Reference
No
The reason this rule exists, often a link to documentation
String
Runbook
No
The actions to be carried out if this rule returns an alert, often a link to documentation
String
Tags
No
Tags used to categorize this rule
List of strings
Tests
No
Unit tests for this rule.
List of maps
DedupPeriodMinutes
No
The time period (in minutes) during which similar events of an alert will be grouped together
15,30,60,180 (3 hours),720 (12 hours), or 1440 (24 hours)
Rule Tests
Tests help validate that your rule will behave as intended and detect the early signs of a breach. In your spec file, add the Tests key with sample cases:
Tests:
  -
    Name: Name to describe our first test
    LogType: LogType.GoesHere
    ExpectedResult: true or false
    Log:
      {
        "hostName": "test-01.prod.acme.io",
        "user": "martin_smith",
        "eventTime": "June 22 5:50:52 PM"
      }
Try to cover as many test cases as possible, including both true and false positives.
Writing Policies
Policies are Python functions to detect misconfigured cloud infrastructure. Returning a value of True indicates this resource is valid and properly configured. Returning False indicates a policy failure, which triggers an alert.
First, write your policy and save it (in your folder of choice) as my_new_policy.py:
def polcy(resource):
  return resource['Region'] != 'us-east-1'
Then, create a specification file using the template below:
AnalysisType: policy
Enabled: true
Filename: my_new_policy.py
PolicyID: Category.Type.MoreInfo
ResourceType:
  - Resource.Type.Here
Severity: Info|Low|Medium|High|Critical
DisplayName: Example Policy to Check the Format of the Spec
Tags:
  - Tags
  - Go
  - Here
Runbook: Find out who changed the spec format.
Reference: https://www.link-to-info.io
Policy Specification Reference
A complete list of policy specification fields:
Field Name
Required
Description
Expected Value
AnalysisType
Yes
Indicates whether this specification is defining a policy or a rule
policy
Enabled
Yes
Whether this policy is enabled
Boolean
FileName
Yes
The path (with file extension) to the python policy body
String
PolicyID
Yes
The unique identifier of the policy
String
ResourceTypes
Yes
What resource types this policy will apply to
List of strings
Severity
Yes
What severity this policy is
One of the following strings: Info, Low, Medium, High, or Critical
ActionDelaySeconds
No
How long (in seconds) to delay auto-remediations and alerts, if configured
Integer
AutoRemediationID
No
The unique identifier of the auto-remediation to execute in case of policy failure
String
AutoRemediationParameters
No
What parameters to pass to the auto-remediation, if one is configured
Map
Description
No
A brief description of the policy
String
DisplayName
No
What name to display in the UI and alerts. The PolicyID will be displayed if this field is not set.
String
Reference
No
The reason this policy exists, often a link to documentation
String
Runbook
No
The actions to be carried out if this policy fails, often a link to documentation
String
Tags
No
Tags used to categorize this policy
List of strings
Tests
No
Unit tests for this policy.
List of maps
Automatic Remediation
Automatic remediations requires two fields to be set in the spec file:
AutoRemediationID: The automatic remediation identifier to enable
AutoRemediationParameters: The expected configurations for the remediation
For a complete list of remediations and their associated configurations, see the remediations page.
Policy Tests
In the spec file, add the following Tests key:
Tests:
  -
    Name: Name to describe our first test.
    ResourceType: AWS.S3.Bucket
    ExpectedResult: true
    Resource:
      {
        "PublicAccessBlockConfiguration": null,
        "Region": "us-east-1",
        "Policy": null,
        "AccountId": "123456789012",
        "LoggingPolicy": {
          "TargetBucket": "access-logs-us-east-1-100",
          "TargetGrants": null,
          "TargetPrefix": "acmecorp-fiancial-data/"
        },
        "EncryptionRules": [
          {
            "ApplyServerSideEncryptionByDefault": {
              "SSEAlgorithm": "AES256",
              "KMSMasterKeyID": null
            }
          }
        ],
        "Arn": "arn:aws:s3:::acmecorp-fiancial-data",
        "Name": "acmecorp-fiancial-data",
        "LifecycleRules": null,
        "ResourceType": "AWS.S3.Bucket",
        "Grants": [
          {
            "Permission": "FULL_CONTROL",
            "Grantee": {
              "URI": null,
              "EmailAddress": null,
              "DisplayName": "admins",
              "Type": "CanonicalUser",
              "ID": "013ae1034i130431431"
            }
          }
        ],
        "Versioning": "Enabled",
        "ResourceId": "arn:aws:s3:::acmecorp-fiancial-data",
        "Tags": {
          "aws:cloudformation:logical-id": "FinancialDataBucket"
        },
        "Owner": {
          "ID": "013ae1034i130431431",
          "DisplayName": "admins"
        },
        "TimeCreated": "2020-06-13T17:16:36.000Z",
        "ObjectLockConfiguration": null,
        "MFADelete": null
      }
The value of Resource can be a JSON object copied directly from the Policies > Resources explorer.
Running Tests
Use the Panther Analysis Tool to load the defined specification files and evaluate unit tests locally:
panther_analysis_tool test --path <folder-name>
To filter rules or policies based on certain attributes:
panther_analysis_tool test --path <folder-name> --filter RuleID=Category.Behavior.MoreInfo
Globals
Global functions allow common logic to be shared across either rules or policies. To declare them as code, add them into the global_helpers folder with a similar pattern to rules and policies.
Globals defined outside of the global_helpers folder will not be loaded.
First, create your Python file (global_helpers/acmecorp.py):
from fnmatch import fnmatch
​
RESOURCE_PATTERN = 'acme-corp-*-[0-9]'
​
​
def matches_internal_naming(resource_name):
  return fnmatch(resource_name, RESOURCE_PATTERN)
Then, create your specification file:
AnalysisType: global
GlobalID: acmecorp
Filename: acmecorp.py
Description: A set of helpers internal to acme-corp
Finally, use this helper in a policy (or a rule):
import acmecorp
​
​
def policy(resource):
  return acmecorp.matches_internal_naming(resource['Name'])
Uploading to Panther
To upload your analysis packs to your Panther instance, run the following command below.
Make sure to configure your environment with valid AWS credentials prior to running the command below. This command will upload based on the exported value of AWS_REGION.
panther_analysis_tool upload --path <path-to-your-rules> --out tmp
Analysis with the same ID are overwritten. Additionally, locally deleted rules/policies will not automatically be deleted in the database and must be removed manually. We recommend setting the Enabled property to false instead of deleting policies or rules for CLI driven workflows.
For Panther Cloud customers, file a support ticket to gain upload access to your Panther environment.

Parsers

Runtime Environment

Last updated 2 months ago

Field Name	Required	Description	Expected Value
`AnalysisType`	Yes	Indicates whether this analysis is a rule, policy, or global	`rule`
`Enabled`	Yes	Whether this rule is enabled	Boolean
`FileName`	Yes	The path (with file extension) to the python rule body	String
`RuleID`	Yes	The unique identifier of the rule	String
`LogTypes`	Yes	The list of logs to apply this rule to	List of strings
`Severity`	Yes	What severity this rule is	One of the following strings: `Info`, `Low`, `Medium`, `High`, or `Critical`
`Description`	No	A brief description of the rule	String
`DisplayName`	No	A friendly name to show in the UI and alerts. The `RuleID` will be displayed if this field is not set.	String
`Reference`	No	The reason this rule exists, often a link to documentation	String
`Runbook`	No	The actions to be carried out if this rule returns an alert, often a link to documentation	String
`Tags`	No	Tags used to categorize this rule	List of strings
`Tests`	No	Unit tests for this rule.	List of maps
`DedupPeriodMinutes`	No	The time period (in minutes) during which similar events of an alert will be grouped together	`15`,`30`,`60`,`180` (3 hours),`720` (12 hours), or `1440` (24 hours)