new asl aws detections

This commit is contained in:
Patrick Bareiss
2024-12-12 16:42:52 +01:00
committed by ljstella
parent 22c3c2dc08
commit ebca30164d
4 changed files with 239 additions and 0 deletions
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name: ASL AWS Create Policy Version to allow all resources
id: 22cc7a62-3884-48c4-82da-592b8199b72f
version: 1
date: '2024-12-12'
author: Patrick Bareiss, Splunk
status: production
type: TTP
description: The following analytic identifies the creation of a new AWS IAM policy version that allows access to all resources. It detects this activity by analyzing AWS CloudTrail logs for the CreatePolicyVersion event with a policy document that grants broad permissions. This behavior is significant because it violates the principle of least privilege, potentially exposing the environment to misuse or abuse. If confirmed malicious, an attacker could gain extensive access to AWS resources, leading to unauthorized actions, data exfiltration, or further compromise of the AWS environment.
data_source: []
search: '`amazon_security_lake` api.operation=CreatePolicy | spath input=api.request.data | spath input=policyDocument | regex Statement{}.Action="\*" | regex Statement{}.Resource="\*" | fillnull | stats count min(_time) as firstTime max(_time) as lastTime by api.operation actor.user.uid http_request.user_agent src_endpoint.ip cloud.region api.request.data | rename actor.user.uid as user, src_endpoint.ip as src_ip, cloud.region as region, http_request.user_agent as user_agent | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`|`asl_aws_create_policy_version_to_allow_all_resources_filter`'
how_to_implement: The detection is based on Amazon Security Lake events from Amazon Web Services (AWS), which is a centralized data lake that provides security-related data from AWS services. To use this detection, you must ingest CloudTrail logs from Amazon Security Lake into Splunk. To run this search, ensure that you ingest events using the latest version of Splunk Add-on for Amazon Web Services (https://splunkbase.splunk.com/app/1876) or the Federated Analytics App.
known_false_positives: While this search has no known false positives, it is possible that an AWS admin has legitimately created a policy to allow a user to access all resources. That said, AWS strongly advises against granting full control to all AWS resources and you must verify this activity.
references:
- https://bishopfox.com/blog/privilege-escalation-in-aws
- https://rhinosecuritylabs.com/aws/aws-privilege-escalation-methods-mitigation-part-2/
drilldown_searches:
- name: View the detection results for - "$user$"
search: '%original_detection_search% | search user = "$user$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$user$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
tags:
analytic_story:
- AWS IAM Privilege Escalation
asset_type: AWS Account
confidence: 70
impact: 70
message: User $user$ created a policy version that allows them to access any resource in their account.
mitre_attack_id:
- T1078.004
- T1078
observable:
- name: user
type: User
role:
- Victim
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
required_fields:
- api.operation
- api.request.data
- actor.user.uid
- http_request.user_agent
- src_endpoint.ip
- src_endpoint.domain
- cloud.region
risk_score: 49
security_domain: network
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1078/aws_create_policy_version/asl_ocsf_cloudtrail.json
sourcetype: aws:cloudtrail:lake
source: aws_asl
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name: ASL AWS CreateAccessKey
id: d130cccd-41fe-483f-a70c-25d238bfce31
version: 1
date: '2024-12-12'
author: Patrick Bareiss, Splunk
status: production
type: Hunting
description: The following analytic identifies the creation of AWS IAM access keys by a user for another user, which can indicate privilege escalation. It leverages AWS CloudTrail logs to detect instances where the user creating the access key is different from the user for whom the key is created. This activity is significant because unauthorized access key creation can allow attackers to establish persistence or exfiltrate data via AWS APIs. If confirmed malicious, this could lead to unauthorized access to AWS services, data exfiltration, and long-term persistence in the environment.
data_source: []
search: '`amazon_security_lake` api.operation=CreateAccessKey | fillnull | stats count min(_time) as firstTime max(_time) as lastTime by api.operation actor.user.uid http_request.user_agent src_endpoint.ip cloud.region | rename actor.user.uid as user, src_endpoint.ip as src_ip, cloud.region as region, http_request.user_agent as user_agent | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` |`asl_aws_createaccesskey_filter`'
how_to_implement: The detection is based on Amazon Security Lake events from Amazon Web Services (AWS), which is a centralized data lake that provides security-related data from AWS services. To use this detection, you must ingest CloudTrail logs from Amazon Security Lake into Splunk. To run this search, ensure that you ingest events using the latest version of Splunk Add-on for Amazon Web Services (https://splunkbase.splunk.com/app/1876) or the Federated Analytics App.
known_false_positives: While this search has no known false positives, it is possible that an AWS admin has legitimately created keys for another user.
references:
- https://bishopfox.com/blog/privilege-escalation-in-aws
- https://rhinosecuritylabs.com/aws/aws-privilege-escalation-methods-mitigation-part-2/
tags:
analytic_story:
- AWS IAM Privilege Escalation
asset_type: AWS Account
confidence: 90
impact: 70
message: User $user$ is attempting to create access keys
mitre_attack_id:
- T1136.003
- T1136
observable:
- name: src_ip
type: IP Address
role:
- Attacker
- name: user
type: User
role:
- Attacker
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
required_fields:
- api.operation
- actor.user.uid
- http_request.user_agent
- src_endpoint.ip
- src_endpoint.domain
- cloud.region
risk_score: 63
security_domain: network
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1078/asl_ocsf_cloudtrail.json
sourcetype: aws:cloudtrail:lake
source: aws_asl
@@ -0,0 +1,64 @@
name: ASL AWS Credential Access GetPasswordData
id: a79b607a-50cc-4704-bb9d-eff280cb78c2
version: 1
date: '2024-12-12'
author: Patrick Bareiss, Splunk
status: production
type: Anomaly
description: The following analytic identifies more than 10 GetPasswordData API calls within a 5-minute window in your AWS account. It leverages AWS CloudTrail logs to detect this activity by counting the distinct instance IDs accessed. This behavior is significant as it may indicate an attempt to retrieve encrypted administrator passwords for running Windows instances, which is a critical security concern. If confirmed malicious, attackers could gain unauthorized access to administrative credentials, potentially leading to full control over the affected instances and further compromise of the AWS environment.
data_source: []
search: '`amazon_security_lake` api.operation=GetPasswordData | spath input=api.request.data | fillnull | stats count min(_time) as firstTime max(_time) as lastTime by api.operation actor.user.uid http_request.user_agent src_endpoint.ip cloud.region instanceId | rename actor.user.uid as user, src_endpoint.ip as src_ip, cloud.region as region, http_request.user_agent as user_agent | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` |`asl_aws_credential_access_getpassworddata_filter`'
how_to_implement: The detection is based on Amazon Security Lake events from Amazon Web Services (AWS), which is a centralized data lake that provides security-related data from AWS services. To use this detection, you must ingest CloudTrail logs from Amazon Security Lake into Splunk. To run this search, ensure that you ingest events using the latest version of Splunk Add-on for Amazon Web Services (https://splunkbase.splunk.com/app/1876) or the Federated Analytics App.
known_false_positives: Administrator tooling or automated scripts may make these calls but it is highly unlikely to make several calls in a short period of time.
references:
- https://attack.mitre.org/techniques/T1552/
- https://stratus-red-team.cloud/attack-techniques/AWS/aws.credential-access.ec2-get-password-data/
drilldown_searches:
- name: View the detection results for - "$user_arn$"
search: '%original_detection_search% | search user_arn = "$user_arn$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$user_arn$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user_arn$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
tags:
analytic_story:
- AWS Identity and Access Management Account Takeover
asset_type: AWS Account
confidence: 70
impact: 70
message: User $user$ is seen to make mulitple `GetPasswordData` API calls
mitre_attack_id:
- T1586
- T1586.003
- T1110
- T1110.001
observable:
- name: src_ip
type: IP Address
role:
- Attacker
- name: user
type: User
role:
- Victim
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
required_fields:
- api.operation
- actor.user.uid
- http_request.user_agent
- src_endpoint.ip
- src_endpoint.domain
- cloud.region
risk_score: 49
security_domain: threat
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1552/aws_getpassworddata/asl_ocsf_cloudtrail.json
sourcetype: aws:cloudtrail:lake
source: aws_asl
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name: ASL AWS Credential Access RDS Password reset
id: d15e9bd9-ef64-4d84-bc04-f62955a9fee8
version: 1
date: '2024-12-12'
author: Patrick Bareiss, Splunk
status: production
type: TTP
description: The following analytic detects the resetting of the master user password for an Amazon RDS DB instance. It leverages AWS CloudTrail logs to identify events where the `ModifyDBInstance` API call includes a new `masterUserPassword` parameter. This activity is significant because unauthorized password resets can grant attackers access to sensitive data stored in production databases, such as credit card information, PII, and healthcare data. If confirmed malicious, this could lead to data breaches, regulatory non-compliance, and significant reputational damage. Immediate investigation is required to determine the legitimacy of the password reset.
data_source: []
search: '`amazon_security_lake` api.operation=ModifyDBInstance OR api.operation=ModifyDBCluster | spath input=api.request.data | search masterUserPassword=* | fillnull | stats count min(_time) as firstTime max(_time) as lastTime by api.operation actor.user.uid http_request.user_agent src_endpoint.ip cloud.region api.request.data | rename actor.user.uid as user, src_endpoint.ip as src_ip, cloud.region as region, http_request.user_agent as user_agent | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` |`asl_aws_credential_access_rds_password_reset_filter`'
how_to_implement: You must install splunk AWS add on and Splunk App for AWS. This search works with AWS CloudTrail logs.
known_false_positives: Users may genuinely reset the RDS password.
references:
- https://aws.amazon.com/premiumsupport/knowledge-center/reset-master-user-password-rds
drilldown_searches:
- name: View the detection results for - "$database_id$"
search: '%original_detection_search% | search database_id = "$database_id$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$database_id$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$database_id$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
tags:
analytic_story:
- AWS Identity and Access Management Account Takeover
asset_type: AWS Account
confidence: 70
impact: 70
message: User $user$ is seen to reset the password for database
mitre_attack_id:
- T1586
- T1586.003
- T1110
observable:
- name: database_id
type: Endpoint
role:
- Victim
- name: src
type: IP Address
role:
- Attacker
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
required_fields:
- api.operation
- api.request.data
- actor.user.uid
- http_request.user_agent
- src_endpoint.ip
- src_endpoint.domain
- cloud.region
risk_score: 49
security_domain: threat
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1110.002/aws_rds_password_reset/asl_ocsf_cloudtrail.json
sourcetype: aws:cloudtrail:lake
source: aws_asl