drlinux/guardduty_to_acl_lambda.py

## guardduty_to_acl_lambda.py
# Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# MIT No Attribution
# Permission is hereby granted, free of charge, to any person obtaining a copy of this
# software and associated documentation files (the "Software"), to deal in the Software
# without restriction, including without limitation the rights to use, copy, modify,
# merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
# PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

import boto3
import math
import time
import json
import datetime
import logging
import os
from boto3.dynamodb.conditions import Key, Attr
from botocore.exceptions import ClientError

logger = logging.getLogger()
logger.setLevel(logging.INFO)

#======================================================================================================================
# Variables
#======================================================================================================================
API_CALL_NUM_RETRIES = 1
ACLMETATABLE = os.environ['ACLMETATABLE']
SNSTOPIC = os.environ['SNSTOPIC']
CLOUDFRONT_IP_SET_ID = os.environ['CLOUDFRONT_IP_SET_ID']
ALB_IP_SET_ID = os.environ['ALB_IP_SET_ID']

#======================================================================================================================
# Auxiliary Functions
#======================================================================================================================
def waf_update_ip_set(waf_type, ip_set_id, source_ip):

    if waf_type == 'alb':
        session = boto3.session.Session(region_name=os.environ['AWS_REGION'])
        waf = session.client('waf-regional')
    elif waf_type == 'cloudfront':
        waf = boto3.client('waf')

    for attempt in range(API_CALL_NUM_RETRIES):
        try:
            response = waf.update_ip_set(IPSetId=ip_set_id,
                ChangeToken=waf.get_change_token()['ChangeToken'],
                Updates=[{
                    'Action': 'INSERT',
                    'IPSetDescriptor': {
                        'Type': 'IPV4',
                        'Value': "%s/32"%source_ip
                    }
                }]
            )
            logger.info("[waf_update_ip_set] added IP %s to IPset %s, WAF type %s successfully..." % (source_ip, ip_set_id, waf_type))
        except Exception as e:
            logger.error(e)
            delay = math.pow(2, attempt)
            logger.info("[waf_update_ip_set] Retrying in %d seconds..." % (delay))
            time.sleep(delay)
        else:
            break
    else:
        logger.info("[waf_update_ip_set] Failed ALL attempts to call API")


def get_netacl_id(subnet_id):

    try:
        ec2 = boto3.client('ec2')
        response = ec2.describe_network_acls(
            Filters=[
                {
                    'Name': 'association.subnet-id',
                    'Values': [
                        subnet_id,
                    ]
                }
            ]
        )


        netacls = response['NetworkAcls'][0]['Associations']

        for i in netacls:
            if i['SubnetId'] == subnet_id:
                netaclid = i['NetworkAclId']

        return netaclid
    except Exception as e:
        return []


def get_nacl_meta(netacl_id):
    ddb = boto3.resource('dynamodb')
    table = ddb.Table(ACLMETATABLE)
    ec2 = boto3.client('ec2')
    response = ec2.describe_network_acls(
        NetworkAclIds=[
            netacl_id,
            ]
    )

    # Get entries in DynamoDB table
    ddbresponse = table.scan()
    ddbentries = response['Items']

    netacl = ddbresponse['NetworkAcls'][0]['Entries']
    naclentries = []

    for i in netacl:
            entries.append(i)

    return naclentries


def update_nacl(netacl_id, host_ip, region):
    logger.info("entering update_nacl, netacl_id=%s, host_ip=%s" % (netacl_id, host_ip))

    ddb = boto3.resource('dynamodb')
    table = ddb.Table(ACLMETATABLE)
    timestamp = int(time.time())

    hostipexists = table.query(
        KeyConditionExpression=Key('NetACLId').eq(netacl_id),
        FilterExpression=Attr('HostIp').eq(host_ip)
    )

    # Get oldest entry in DynamoDB table
    oldestrule = table.query(
        KeyConditionExpression=Key('NetACLId').eq(netacl_id),
        ScanIndexForward=True, # true = ascending, false = descending
        Limit=1,
    )

    # Is HostIp already in table?
    if len(hostipexists['Items']) > 0:
        logger.info("log -- host IP %s already in table... exiting NACL update." % (host_ip))

    else:

        # Get current NACL entries in DDB
        response = table.query(
            KeyConditionExpression=Key('NetACLId').eq(netacl_id)
        )

        # Get all the entries for NACL
        naclentries = response['Items']

        # Find oldest rule and current counter
        if naclentries:
            oldruleno = int((oldestrule)['Items'][0]['RuleNo'])
            oldrulets = int((oldestrule)['Items'][0]['CreatedAt'])
            rulecounter = max(naclentries, key=lambda x:x['RuleNo'])['RuleNo']
            rulecount = response['Count']

            # Set the rule number
            if int(rulecounter) < 80:
                newruleno = int(rulecounter) + 1

                # Create NACL rule and DDB state entry
                create_netacl_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno)
                create_ddb_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno, region=region)

                logger.info("log -- add new rule %s, HostIP %s, to NACL %s." % (newruleno, host_ip, netacl_id))
                logger.info("log -- rule count for NACL %s is %s." % (netacl_id, int(rulecount) + 1))

            else:
                newruleno = oldruleno

                # Delete old NACL rule and DDB state entry
                delete_netacl_rule(netacl_id=netacl_id, rule_no=oldruleno)
                delete_ddb_rule(netacl_id=netacl_id, created_at=oldrulets)

                logger.info("log -- delete rule %s, from NACL %s." % (oldruleno, netacl_id))

                # Create NACL rule and DDB state entry
                create_netacl_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno)
                create_ddb_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno, region=region)

                logger.info("log -- add new rule %s, HostIP %s, to NACL %s." % (newruleno, host_ip, netacl_id))
                logger.info("log -- rule count for NACL %s is %s." % (netacl_id, rulecount))

        else:
            # No entries in DDB Table start from 71
            newruleno = 71
            oldruleno = []
            rulecount = 0

            # Create NACL rule and DDB state entry
            create_netacl_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno)
            create_ddb_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno, region=region)

            logger.info("log -- add new rule %s, HostIP %s, to NACL %s." % (newruleno, host_ip, netacl_id))
            logger.info("log -- rule count for NACL %s is %s." % (netacl_id, int(rulecount) + 1))

        if rulecount > 10:
            delete_netacl_rule(netacl_id=netacl_id, rule_no=oldruleno)

            logger.info("log -- delete rule %s, from NACL %s." % (oldruleno, netacl_id))
            logger.info("log -- rule count for NACL %s is %s." % (netacl_id, int(rulecount) + 1))

        if response['ResponseMetadata']['HTTPStatusCode'] == 200:
            return True
        else:
            return False


def create_netacl_rule(netacl_id, host_ip, rule_no):

    ec2 = boto3.resource('ec2')
    network_acl = ec2.NetworkAcl(netacl_id)

    response = network_acl.create_entry(
    CidrBlock = host_ip + '/32',
    Egress=False,
    PortRange={
        'From': 0,
        'To': 65535
    },
    Protocol='-1',
    RuleAction='deny',
    RuleNumber= rule_no
    )

    if response['ResponseMetadata']['HTTPStatusCode'] == 200:
        return True
    else:
        return False


def delete_netacl_rule(netacl_id, rule_no):

    ec2 = boto3.resource('ec2')
    network_acl = ec2.NetworkAcl(netacl_id)

    response = network_acl.delete_entry(
        Egress=False,
        RuleNumber=rule_no
    )

    if response['ResponseMetadata']['HTTPStatusCode'] == 200:
        return True
    else:
        return False

def create_ddb_rule(netacl_id, host_ip, rule_no, region):

    ddb = boto3.resource('dynamodb')
    table = ddb.Table(ACLMETATABLE)
    timestamp = int(time.time())

    response = table.put_item(
        Item={
            'NetACLId': netacl_id,
            'CreatedAt': timestamp,
            'HostIp': str(host_ip),
            'RuleNo': str(rule_no),
            'Region': str(region)
            }
        )

    if response['ResponseMetadata']['HTTPStatusCode'] == 200:
        return True
    else:
        return False


def delete_ddb_rule(netacl_id, created_at):

    ddb = boto3.resource('dynamodb')
    table = ddb.Table(ACLMETATABLE)
    timestamp = int(time.time())

    response = table.delete_item(
        Key={
            'NetACLId': netacl_id,
            'CreatedAt': int(created_at)
            }
        )

    if response['ResponseMetadata']['HTTPStatusCode'] == 200:
        return True
    else:
        return False

def admin_notify(iphost, findingtype, naclid, region, instanceid):

    MESSAGE = ("GuardDuty to ACL Event Info:\r\n"
                 "Suspicious activity detected from host " + iphost + " due to " + findingtype + "."
                 "  The following ACL resources were targeted for update as needed; "
                 "CloudFront IP Set: " + CLOUDFRONT_IP_SET_ID + ", "
                 "Regional IP Set: " + ALB_IP_SET_ID + ", "
                 "VPC NACL: " + naclid + ", "
                 "EC2 Instance: " + instanceid + ", "
                 "Region: " + region + ". "
                )

    sns = boto3.client(service_name="sns")

    # Try to send the notification.
    try:

        sns.publish(
            TopicArn = SNSTOPIC,
            Message = MESSAGE,
            Subject='AWS GD2ACL Alert'
        )
        logger.info("Notification sent to SNS Topic: %s" % (SNSTOPIC))

    # Display an error if something goes wrong.
    except ClientError as e:
        logger.error('Error sending notification.')
        raise


#======================================================================================================================
# Lambda Entry Point
#======================================================================================================================


def lambda_handler(event, context):

    logger.info("log -- Event: %s " % json.dumps(event))

    try:

        if event["detail"]["type"] == 'Recon:EC2/PortProbeUnprotectedPort':
            Region = event["region"]
            SubnetId = event["detail"]["resource"]["instanceDetails"]["networkInterfaces"][0]["subnetId"]
            HostIp = event["detail"]["service"]["action"]["portProbeAction"]["portProbeDetails"][0]["remoteIpDetails"]["ipAddressV4"]
            instanceID = event["detail"]["resource"]["instanceDetails"]["instanceId"]
            NetworkAclId = get_netacl_id(subnet_id=SubnetId)

        else:
            Region = event["region"]
            SubnetId = event["detail"]["resource"]["instanceDetails"]["networkInterfaces"][0]["subnetId"]
            HostIp = event["detail"]["service"]["action"]["networkConnectionAction"]["remoteIpDetails"]["ipAddressV4"]
            instanceID = event["detail"]["resource"]["instanceDetails"]["instanceId"]
            NetworkAclId = get_netacl_id(subnet_id=SubnetId)

        if NetworkAclId:
            # Update global and regional IP Sets
            waf_update_ip_set('alb', os.environ['ALB_IP_SET_ID'], HostIp)
            waf_update_ip_set('cloudfront', os.environ['CLOUDFRONT_IP_SET_ID'], HostIp)

            # Update VPC NACL
            response = update_nacl(netacl_id=NetworkAclId,host_ip=HostIp, region=Region)

            #Send Notification
            admin_notify(HostIp, event["detail"]["type"], NetworkAclId, Region, instanceid = instanceID)

            logger.info("processing GuardDuty finding completed successfully")

        else:
            logger.info("Unable to determine NetworkAclId for instanceID: %s, HostIp: %s, SubnetId: %s. Confirm resources exist." % (instanceID, HostIp, SubnetId))
            pass

    except Exception as e:
        logger.error('Something went wrong.')
        raise
	# Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
	#
	# MIT No Attribution
	# Permission is hereby granted, free of charge, to any person obtaining a copy of this
	# software and associated documentation files (the "Software"), to deal in the Software
	# without restriction, including without limitation the rights to use, copy, modify,
	# merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
	# permit persons to whom the Software is furnished to do so.
	#
	# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
	# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
	# PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
	# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
	# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
	# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

	import boto3
	import math
	import time
	import json
	import datetime
	import logging
	import os
	from boto3.dynamodb.conditions import Key, Attr
	from botocore.exceptions import ClientError

	logger = logging.getLogger()
	logger.setLevel(logging.INFO)

	#======================================================================================================================
	# Variables
	#======================================================================================================================
	API_CALL_NUM_RETRIES = 1
	ACLMETATABLE = os.environ['ACLMETATABLE']
	SNSTOPIC = os.environ['SNSTOPIC']
	CLOUDFRONT_IP_SET_ID = os.environ['CLOUDFRONT_IP_SET_ID']
	ALB_IP_SET_ID = os.environ['ALB_IP_SET_ID']

	#======================================================================================================================
	# Auxiliary Functions
	#======================================================================================================================
	def waf_update_ip_set(waf_type, ip_set_id, source_ip):

	if waf_type == 'alb':
	session = boto3.session.Session(region_name=os.environ['AWS_REGION'])
	waf = session.client('waf-regional')
	elif waf_type == 'cloudfront':
	waf = boto3.client('waf')

	for attempt in range(API_CALL_NUM_RETRIES):
	try:
	response = waf.update_ip_set(IPSetId=ip_set_id,
	ChangeToken=waf.get_change_token()['ChangeToken'],
	Updates=[{
	'Action': 'INSERT',
	'IPSetDescriptor': {
	'Type': 'IPV4',
	'Value': "%s/32"%source_ip
	}
	}]
	)
	logger.info("[waf_update_ip_set] added IP %s to IPset %s, WAF type %s successfully..." % (source_ip, ip_set_id, waf_type))
	except Exception as e:
	logger.error(e)
	delay = math.pow(2, attempt)
	logger.info("[waf_update_ip_set] Retrying in %d seconds..." % (delay))
	time.sleep(delay)
	else:
	break
	else:
	logger.info("[waf_update_ip_set] Failed ALL attempts to call API")


	def get_netacl_id(subnet_id):

	try:
	ec2 = boto3.client('ec2')
	response = ec2.describe_network_acls(
	Filters=[
	{
	'Name': 'association.subnet-id',
	'Values': [
	subnet_id,
	]
	}
	]
	)


	netacls = response['NetworkAcls'][0]['Associations']

	for i in netacls:
	if i['SubnetId'] == subnet_id:
	netaclid = i['NetworkAclId']

	return netaclid
	except Exception as e:
	return []


	def get_nacl_meta(netacl_id):
	ddb = boto3.resource('dynamodb')
	table = ddb.Table(ACLMETATABLE)
	ec2 = boto3.client('ec2')
	response = ec2.describe_network_acls(
	NetworkAclIds=[
	netacl_id,
	]
	)

	# Get entries in DynamoDB table
	ddbresponse = table.scan()
	ddbentries = response['Items']

	netacl = ddbresponse['NetworkAcls'][0]['Entries']
	naclentries = []

	for i in netacl:
	entries.append(i)

	return naclentries


	def update_nacl(netacl_id, host_ip, region):
	logger.info("entering update_nacl, netacl_id=%s, host_ip=%s" % (netacl_id, host_ip))

	ddb = boto3.resource('dynamodb')
	table = ddb.Table(ACLMETATABLE)
	timestamp = int(time.time())

	hostipexists = table.query(
	KeyConditionExpression=Key('NetACLId').eq(netacl_id),
	FilterExpression=Attr('HostIp').eq(host_ip)
	)

	# Get oldest entry in DynamoDB table
	oldestrule = table.query(
	KeyConditionExpression=Key('NetACLId').eq(netacl_id),
	ScanIndexForward=True, # true = ascending, false = descending
	Limit=1,
	)

	# Is HostIp already in table?
	if len(hostipexists['Items']) > 0:
	logger.info("log -- host IP %s already in table... exiting NACL update." % (host_ip))

	else:

	# Get current NACL entries in DDB
	response = table.query(
	KeyConditionExpression=Key('NetACLId').eq(netacl_id)
	)

	# Get all the entries for NACL
	naclentries = response['Items']

	# Find oldest rule and current counter
	if naclentries:
	oldruleno = int((oldestrule)['Items'][0]['RuleNo'])
	oldrulets = int((oldestrule)['Items'][0]['CreatedAt'])
	rulecounter = max(naclentries, key=lambda x:x['RuleNo'])['RuleNo']
	rulecount = response['Count']

	# Set the rule number
	if int(rulecounter) < 80:
	newruleno = int(rulecounter) + 1

	# Create NACL rule and DDB state entry
	create_netacl_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno)
	create_ddb_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno, region=region)

	logger.info("log -- add new rule %s, HostIP %s, to NACL %s." % (newruleno, host_ip, netacl_id))
	logger.info("log -- rule count for NACL %s is %s." % (netacl_id, int(rulecount) + 1))

	else:
	newruleno = oldruleno

	# Delete old NACL rule and DDB state entry
	delete_netacl_rule(netacl_id=netacl_id, rule_no=oldruleno)
	delete_ddb_rule(netacl_id=netacl_id, created_at=oldrulets)

	logger.info("log -- delete rule %s, from NACL %s." % (oldruleno, netacl_id))

	# Create NACL rule and DDB state entry
	create_netacl_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno)
	create_ddb_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno, region=region)

	logger.info("log -- add new rule %s, HostIP %s, to NACL %s." % (newruleno, host_ip, netacl_id))
	logger.info("log -- rule count for NACL %s is %s." % (netacl_id, rulecount))

	else:
	# No entries in DDB Table start from 71
	newruleno = 71
	oldruleno = []
	rulecount = 0

	# Create NACL rule and DDB state entry
	create_netacl_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno)
	create_ddb_rule(netacl_id=netacl_id, host_ip=host_ip, rule_no=newruleno, region=region)

	logger.info("log -- add new rule %s, HostIP %s, to NACL %s." % (newruleno, host_ip, netacl_id))
	logger.info("log -- rule count for NACL %s is %s." % (netacl_id, int(rulecount) + 1))

	if rulecount > 10:
	delete_netacl_rule(netacl_id=netacl_id, rule_no=oldruleno)

	logger.info("log -- delete rule %s, from NACL %s." % (oldruleno, netacl_id))
	logger.info("log -- rule count for NACL %s is %s." % (netacl_id, int(rulecount) + 1))

	if response['ResponseMetadata']['HTTPStatusCode'] == 200:
	return True
	else:
	return False


	def create_netacl_rule(netacl_id, host_ip, rule_no):

	ec2 = boto3.resource('ec2')
	network_acl = ec2.NetworkAcl(netacl_id)

	response = network_acl.create_entry(
	CidrBlock = host_ip + '/32',
	Egress=False,
	PortRange={
	'From': 0,
	'To': 65535
	},
	Protocol='-1',
	RuleAction='deny',
	RuleNumber= rule_no
	)

	if response['ResponseMetadata']['HTTPStatusCode'] == 200:
	return True
	else:
	return False


	def delete_netacl_rule(netacl_id, rule_no):

	ec2 = boto3.resource('ec2')
	network_acl = ec2.NetworkAcl(netacl_id)

	response = network_acl.delete_entry(
	Egress=False,
	RuleNumber=rule_no
	)

	if response['ResponseMetadata']['HTTPStatusCode'] == 200:
	return True
	else:
	return False

	def create_ddb_rule(netacl_id, host_ip, rule_no, region):

	ddb = boto3.resource('dynamodb')
	table = ddb.Table(ACLMETATABLE)
	timestamp = int(time.time())

	response = table.put_item(
	Item={
	'NetACLId': netacl_id,
	'CreatedAt': timestamp,
	'HostIp': str(host_ip),
	'RuleNo': str(rule_no),
	'Region': str(region)
	}
	)

	if response['ResponseMetadata']['HTTPStatusCode'] == 200:
	return True
	else:
	return False


	def delete_ddb_rule(netacl_id, created_at):

	ddb = boto3.resource('dynamodb')
	table = ddb.Table(ACLMETATABLE)
	timestamp = int(time.time())

	response = table.delete_item(
	Key={
	'NetACLId': netacl_id,
	'CreatedAt': int(created_at)
	}
	)

	if response['ResponseMetadata']['HTTPStatusCode'] == 200:
	return True
	else:
	return False

	def admin_notify(iphost, findingtype, naclid, region, instanceid):

	MESSAGE = ("GuardDuty to ACL Event Info:\r\n"
	"Suspicious activity detected from host " + iphost + " due to " + findingtype + "."
	" The following ACL resources were targeted for update as needed; "
	"CloudFront IP Set: " + CLOUDFRONT_IP_SET_ID + ", "
	"Regional IP Set: " + ALB_IP_SET_ID + ", "
	"VPC NACL: " + naclid + ", "
	"EC2 Instance: " + instanceid + ", "
	"Region: " + region + ". "
	)

	sns = boto3.client(service_name="sns")

	# Try to send the notification.
	try:

	sns.publish(
	TopicArn = SNSTOPIC,
	Message = MESSAGE,
	Subject='AWS GD2ACL Alert'
	)
	logger.info("Notification sent to SNS Topic: %s" % (SNSTOPIC))

	# Display an error if something goes wrong.
	except ClientError as e:
	logger.error('Error sending notification.')
	raise



	#======================================================================================================================
	# Lambda Entry Point
	#======================================================================================================================


	def lambda_handler(event, context):

	logger.info("log -- Event: %s " % json.dumps(event))

	try:

	if event["detail"]["type"] == 'Recon:EC2/PortProbeUnprotectedPort':
	Region = event["region"]
	SubnetId = event["detail"]["resource"]["instanceDetails"]["networkInterfaces"][0]["subnetId"]
	HostIp = event["detail"]["service"]["action"]["portProbeAction"]["portProbeDetails"][0]["remoteIpDetails"]["ipAddressV4"]
	instanceID = event["detail"]["resource"]["instanceDetails"]["instanceId"]
	NetworkAclId = get_netacl_id(subnet_id=SubnetId)

	else:
	Region = event["region"]
	SubnetId = event["detail"]["resource"]["instanceDetails"]["networkInterfaces"][0]["subnetId"]
	HostIp = event["detail"]["service"]["action"]["networkConnectionAction"]["remoteIpDetails"]["ipAddressV4"]
	instanceID = event["detail"]["resource"]["instanceDetails"]["instanceId"]
	NetworkAclId = get_netacl_id(subnet_id=SubnetId)

	if NetworkAclId:
	# Update global and regional IP Sets
	waf_update_ip_set('alb', os.environ['ALB_IP_SET_ID'], HostIp)
	waf_update_ip_set('cloudfront', os.environ['CLOUDFRONT_IP_SET_ID'], HostIp)

	# Update VPC NACL
	response = update_nacl(netacl_id=NetworkAclId,host_ip=HostIp, region=Region)

	#Send Notification
	admin_notify(HostIp, event["detail"]["type"], NetworkAclId, Region, instanceid = instanceID)

	logger.info("processing GuardDuty finding completed successfully")

	else:
	logger.info("Unable to determine NetworkAclId for instanceID: %s, HostIp: %s, SubnetId: %s. Confirm resources exist." % (instanceID, HostIp, SubnetId))
	pass

	except Exception as e:
	logger.error('Something went wrong.')
	raise