terraform-aws-cloudtrail-alarms

This module creates a number of Cloudwatch alarms that alert on Cloudtrail events; they are meant to provide compliance with the AWS CIS benchmark.

This module uses Cloudtrail logs which have been written to a Cloudwatch logs group; this means for organizations with an organization Cloudtrail, you only need to put this in the master account.

The following alarms are available in this module; all can be toggled on or off, but by default all alarms are active.

• AWS Config changes
• Cloudtrail config changes
• Console signin failures
• Disabling or deleting CMK
• IAM changes
• Network ACL changes
• Network gateway changes
• No MFA console logins
• Root account usage
• Route table changes
• S3 bucket policy changes
• Security group changes
• Unauthorized API calls
• VPC changes

These alarms were adapted from those in https://github.com/nozaq/terraform-aws-secure-baseline.

Usage

module "cloudtrail_alarms" {
  source         = "trussworks/cloudtrail-alarms/aws"
  version        = "~> 1.0.0"

  alarm_sns_topic_arn = aws_sns_topic.my_alerts.arn
}

Requirements

Name	Version
terraform	>= 1.0
aws	>= 3.0

Providers

Name	Version
aws	>= 3.0

Modules

No modules.

Resources

Name	Type
aws_cloudwatch_log_metric_filter.aws_config_changes	resource
aws_cloudwatch_log_metric_filter.cloudtrail_cfg_changes	resource
aws_cloudwatch_log_metric_filter.console_signin_failures	resource
aws_cloudwatch_log_metric_filter.disable_or_delete_cmk	resource
aws_cloudwatch_log_metric_filter.iam_changes	resource
aws_cloudwatch_log_metric_filter.nacl_changes	resource
aws_cloudwatch_log_metric_filter.network_gw_changes	resource
aws_cloudwatch_log_metric_filter.no_mfa_console_signin_assumed_role	resource
aws_cloudwatch_log_metric_filter.no_mfa_console_signin_no_assumed_role	resource
aws_cloudwatch_log_metric_filter.root_usage	resource
aws_cloudwatch_log_metric_filter.route_table_changes	resource
aws_cloudwatch_log_metric_filter.s3_bucket_policy_changes	resource
aws_cloudwatch_log_metric_filter.security_group_changes	resource
aws_cloudwatch_log_metric_filter.unauthorized_api_calls	resource
aws_cloudwatch_log_metric_filter.vpc_changes	resource
aws_cloudwatch_metric_alarm.aws_config_changes	resource
aws_cloudwatch_metric_alarm.cloudtrail_cfg_changes	resource
aws_cloudwatch_metric_alarm.console_signin_failures	resource
aws_cloudwatch_metric_alarm.disable_or_delete_cmk	resource
aws_cloudwatch_metric_alarm.iam_changes	resource
aws_cloudwatch_metric_alarm.nacl_changes	resource
aws_cloudwatch_metric_alarm.network_gw_changes	resource
aws_cloudwatch_metric_alarm.no_mfa_console_signin	resource
aws_cloudwatch_metric_alarm.root_usage	resource
aws_cloudwatch_metric_alarm.route_table_changes	resource
aws_cloudwatch_metric_alarm.s3_bucket_policy_changes	resource
aws_cloudwatch_metric_alarm.security_group_changes	resource
aws_cloudwatch_metric_alarm.unauthorized_api_calls	resource
aws_cloudwatch_metric_alarm.vpc_changes	resource

Inputs

Name	Description	Type	Default	Required
alarm_namespace	Namespace for generated Cloudwatch alarms	string	"CISBenchmark"	no
alarm_prefix	Prefix for the alarm name	string	""	no
alarm_sns_topic_arn	SNS topic ARN for generated alarms	string	n/a	yes
aws_config_changes	Toggle AWS Config changes alarm	bool	true	no
cloudtrail_cfg_changes	Toggle Cloudtrail config changes alarm	bool	true	no
cloudtrail_log_group_name	Cloudwatch log group name for Cloudtrail logs	string	"cloudtrail-events"	no
console_signin_failures	Toggle console signin failures alarm	bool	true	no
disable_assumed_role_login_alerts	Toggle to disable assumed role console login alerts - violates CIS Benchmark	bool	false	no
disable_or_delete_cmk	Toggle disable or delete CMK alarm	bool	true	no
iam_changes	Toggle IAM changes alarm	bool	true	no
nacl_changes	Toggle network ACL changes alarm	bool	true	no
network_gw_changes	Toggle network gateway changes alarm	bool	true	no
no_mfa_console_login	Toggle no MFA console login alarm	bool	true	no
root_usage	Toggle root usage alarm	bool	true	no
route_table_changes	Toggle route table changes alarm	bool	true	no
s3_bucket_policy_changes	Toggle S3 bucket policy changes alarm	bool	true	no
security_group_changes	Toggle security group changes alarm	bool	true	no
tags	Tags for resources created	map(string)	{}	no
unauthorized_api_calls	Toggle unauthorized api calls alarm	bool	true	no
vpc_changes	Toggle VPC changes alarm	bool	true	no

Outputs

No outputs.