* [Rule Tunings] Reduce Usage of Flattened Fields in AWS Rules
This PR is in part a response to the following issues regarding the future of flattened fields in AWS, which we use as an essential part of our ruleset. However, this is also in response to the ongoing ruleset audit. Some of the flattened fields used are not truly necessary for the alert to trigger or can be replaced by a different field. Those changes have been made here and our non_ecs file has been edited to remove the unnecessary fields. Additionally, flattened fields have been removed from highlighted fields, and from investigation guides.
* Update discovery_ec2_userdata_request_for_ec2_instance.toml
updated_date
* Update execution_ssm_sendcommand_by_rare_user.toml
updated_date
* Update non-ecs-schema.json
add necessary field for ModifyInstanceAttribute action
* Update persistence_ec2_security_group_configuration_change_detection.toml
added missing event.action AuthorizeSecurityGroupIngress, narrowed scope for ModifyInstanceAttribute action by adding a necessary flattened_field
* Update privilege_escalation_iam_customer_managed_policy_attached_to_role.toml
updated min_stack_version for new field target.entity.id
* Update privilege_escalation_iam_customer_managed_policy_attached_to_role.toml
* Update privilege_escalation_iam_update_assume_role_policy.toml
updating min_stack to account of target.entity.id field
* Update impact_s3_excessive_object_encryption_with_sse_c.toml
adding highlighted fields
* Update rules/integrations/aws/exfiltration_dynamodb_table_exported_to_s3.toml
* Apply suggestions from code review
---------
Co-authored-by: Mika Ayenson, PhD <Mikaayenson@users.noreply.github.com>
Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
* new rule Microsoft Entra ID Suspicious Cloud Device Registration
* adjusted backticks in non-ecs and rule
* linted
* adjusted uuid; bumped patch version
* [Rule Tunings] AWS SSM Command Document Created by Rare User
## AWS SSM Command Document Created by Rare User
Rule executes as expected and has very few alerts in telemetry. However, it is one of the rules timing out occasionally.
- reduced execution window
- reduced new terms history window
- replaced wildcards with the flattened field in the query, which should improve performance
- replaced `aws.cloudtrail.user_identity.arn` with combination of `cloud.account.id` and `user.name` to account for Assumed Roles. This will only evaluate the role instead of each individual role session, which will improve performance.
- added investigation fields
- corrected tags
- added mitre technique
## AWS SSM `SendCommand` Execution by Rare User"
- added investigation fields
- added tag
* update pyproject.toml
update pyproject.toml version
* tuning rule Suspicious Microsoft 365 Mail Access by Unusual ClientAppId
* adjusted tactic tag
* updating patch version
* updating patch version
* bumping patch version
* [Rule Tuning] AWS EC2 User Data Retrieval for EC2 Instance
- changed execution window
- explicitly added flattened fields to query, to reduce wildcard usage
- added investigation fields
- changed new terms field to evaluate `user.name` over `aws.cloudtrail.user_identity.arn` so that only the role name for Assumed Role identitites is being evaluated instead of each individual session. This should greatly impact performance as most instances of this rule in telemetry is triggered by Assumed Roles.
* Apply suggestions from code review
* remove instanceId parameter
Co-authored-by: Mika Ayenson, PhD <Mikaayenson@users.noreply.github.com>
---------
Co-authored-by: Mika Ayenson, PhD <Mikaayenson@users.noreply.github.com>
* [New Rule] AWS CloudTrail Log Evasion
Identifies the evasion of cloudtrail logging for IAM actions involving policy creation, modification or attachment. When making certain policy-related API calls, an adversary may pad the associated policy document with whitespaces to trigger CloudTrail’s logging size constraints, resulting in incomplete logging where critical details about the policy are omitted. By exploiting this gap, threat actors can bypass monitoring performed through CloudTrail and can effectively obscure unauthorized changes. This rule looks for IAM API calls with the requestParameters property containing reason:”requestParameters too large” and omitted:true.
This is a known gap in AWS with no immediate remediation steps. While the size constraint issue affects additional services, IAM policy-related API calls are the only that pose a security risk which is why this rule is scoped specifically to `event.provider: iam.amazonaws.com`. For additional background on the evasion technique refer to Permisso's [research](https://permiso.io/blog/cloudtrail-logging-evasion-where-policy-size-matters).
* aligning IG and rule name
* added investigation fields
added investigation fields
* change severity
* updating pyproject version
* [Rule Tuning] AWS EC2 Deprecated AMI Discovery
Rule triggers as expected
Telemetry shows only known FP risks from tools that are intentionally including deprecated AMIs in their searches (these should be excluded by customers)
- changed the query to reduce use of multiple wildcards
- changed the execution window
- removed unnecessary parts of IG
- added to the highlighted fields
* update non-ecs-schema.json
update non-ecs-schema.json with field "aws.cloudtrail.flattened.request_parameters.ownersSet.items.owner"
* update version in pyproject.toml
update version in pyproject.toml
* Update pyproject.toml
* new rule 'Suspicious Email Access by First-Party Application via Microsoft Graph'
* updated patch version
---------
Co-authored-by: Colson Wilhoit <48036388+DefSecSentinel@users.noreply.github.com>
* tuning 'Azure Service Principal Credentials Added'
* updated patch version
* added investigation guide
* updating patch version
* updating patch version
* tuning 'Microsoft Entra ID Rare Authentication Requirement for Principal User'
* updated MITRE ATT&CK mappings
* updated index target
* updated patch version
* updating patch version
* bumping patch version
* updating patch version
* new rules for AWS DynamoDB data exfiltration
* bumping patch version
* adjusting investigation guide
* updating patch version
* updating patch version
* updating patch version
---------
Co-authored-by: Colson Wilhoit <48036388+DefSecSentinel@users.noreply.github.com>
* rule tuning 'First Occurrence of Entra ID Auth via DeviceCode Protocol'
* bumping patch version
* fixed investigation guide unit test failure
* bump patch
* [Rule Tuning] AWS Monthly Rule Tunings
* Adding several more AWS tunings
* updating patch version
* updating non-ecs type to boolean
* fixed cloudtrail index
* new rule 'AWS EC2 Deprecated AMI Discovery'
* updated type
* updated non-ecs; bumped package version
* updated query
* added missing index
* updated patch version
* adding new rule 'AWS IAM Customer-Managed Policy Attached to Role by Rare User'
* adding investigation guide tag
* adds new hunting query
* updated notes
* changed name
* adjusting pyproject.toml version
* [New Rule] [Rule Tuning] AWS STS AssumeRole with New MFA Device, AWS IAM Deactivation of MFA Device
New terms rule for new MFA device with AssumeRole action. Rule tuning to add MITRE technique to "AWS IAM Deactivation of MFA Device"
* add serialNumber to non-ecs schema file
* fixed misspelled toml file name
* Update rules/integrations/aws/persistence_sts_assume_role_with_new_mfa.toml
Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
---------
Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
* adding new rule for Okta public client app OAuth token request with client credentials
* Update detection_rules/etc/non-ecs-schema.json
* changing new terms to okta.actor.display_name
* linted; added references
* [Rule BugFix] Google Workspace Oauth2 new app
In our extended testing the changed rule with latest Google Workspace
integration generates the following errors which make the rule fail everytime:
```
unsupported_operation_exception: [wildcard] queries are not currently supported on keyed [flattened] fields.
```
After careful investigation this happens since the field google_workspace.token.scope.data is a flattened
JSON filed that contains one or more key/value pairs and ES does not support wildcard matches withing flattened
fields as the error suggests.
We instead query the whole field (that contains the flattened fields) with the wildcard characters and achieve
the same outcome without the error.
* [Rule BugFix] Google Workspace Oauth2 new app update (#3436)
In our extended testing the changed rule with latest Google Workspace
integration generates the following errors which make the rule fail everytime:
```
unsupported_operation_exception: [wildcard] queries are not currently supported on keyed [flattened] fields.
```
After careful investigation this happens since the field google_workspace.token.scope.data is a flattened
JSON filed that contains one or more key/value pairs and ES does not support wildcard matches withing flattened
fields as the error suggests.
We instead query the whole field (that contains the flattened fields) with the wildcard characters and achieve
the same outcome without the error.
---------
Co-authored-by: Mika Ayenson <Mikaayenson@users.noreply.github.com>
Co-authored-by: Terrance DeJesus <99630311+terrancedejesus@users.noreply.github.com>
* [New Rules] UEBA GItHub BBRs and Rules
A new set of BBRs and rules that will be used to trigger new UEBA GitHub threshold Rules.
* Update rules/integrations/github/impact_github_member_removed_from_organization.toml
* Apply suggestions from code review
Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
* edited BBR rules
-removed newly added member rule
* updated integration manifests and schemas
* Updated min_stack for some rules based on newest GitHub integration schema manifest
* testing min_stack bump to 8.8 for new fields
* removing offending rule to troubleshoot seperately
* added UEBA tags and created UEBA threshold rule
* updated non-ecs-schema to add signal.rule.tags
* updated non-ecs-schema with kibana.alert.workflow_status
* updated rule.threat.tactic
* added user.name to non-ecs-schema
* added quotes to kibana.alert.workflow_status value
* removed trailing space from rule name
* update tags and optimize query for UEBA threshold rule
* removed integration field from Higher-Order rule
* Apply suggestions from code review
Co-authored-by: Terrance DeJesus <99630311+terrancedejesus@users.noreply.github.com>
* adjusted new_terms order and rule types based on review feedback
* Apply suggestions from code review
Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
* remove user.name from detection_rules/etc/non-ecs-schema.json
* fix json formatting
---------
Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
Co-authored-by: Colson Wilhoit <48036388+DefSecSentinel@users.noreply.github.com>
Co-authored-by: Terrance DeJesus <99630311+terrancedejesus@users.noreply.github.com>
Co-authored-by: Justin Ibarra <16747370+brokensound77@users.noreply.github.com>
Co-authored-by: Mika Ayenson <Mikaayenson@users.noreply.github.com>
* adding new rule 'Google Workspace New OAuth Login from Custom Application'
* changed name and 'custom' to 'third-party'
* Update rules/integrations/google_workspace/defense_evasion_google_workspace_new_oauth_login_from_third_party_application.toml
* Update rules/integrations/google_workspace/defense_evasion_google_workspace_new_oauth_login_from_third_party_application.toml
* updated non-ecs
Mika Ayenson, PhD