First Time AWS Cloudformation Stack Creation by User

calendar Jul 31, 2024 · Domain: Cloud Data Source: AWS Data Source: Amazon Web Services Data Source: Cloudformation Use Case: Asset Visibility Tactic: Execution  ·
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This rule detects the first time a principal calls AWS Cloudwatch CreateStack or CreateStackSet API. Cloudformation is used to create a single collection of cloud resources called a stack, via a defined template file. An attacker with the appropriate privileges could leverage Cloudformation to create specific resources needed to further exploit the environment. This is a new terms rule that looks for the first instance of this behavior in the last 10 days for a role or IAM user within a particular account.

Elastic rule (View on GitHub)

 1[metadata]
 2creation_date = "2020/07/25"
 3integration = ["aws"]
 4maturity = "production"
 5min_stack_comments = "Multiple field support in the New Terms rule type was added in Elastic 8.6"
 6min_stack_version = "8.6.0"
 7updated_date = "2024/07/31"
 8
 9[rule]
10author = ["Elastic"]
11description = """
12This rule detects the first time a principal calls AWS Cloudwatch `CreateStack` or `CreateStackSet` API. Cloudformation is used to create a single collection of cloud resources called a stack, via a defined template file. An attacker with the appropriate privileges could leverage Cloudformation to create specific resources needed to further exploit the environment. This is a new terms rule that looks for the first instance of this behavior in the last 10 days for a role or IAM user within a particular account.
13"""
14false_positives = [
15    """
16    Verify whether the user identity should be using the `CreateStack` or `CreateStackSet` APIs. If known behavior is causing false positives, it can be exempted from the rule. The "history_window_start" value can be modified to reflect the expected frequency of known activity within a particular environment.
17    """,
18]
19from = "now-6m"
20index = ["filebeat-*", "logs-aws.cloudtrail-*"]
21language = "kuery"
22license = "Elastic License v2"
23name = "First Time AWS Cloudformation Stack Creation by User"
24references = [
25    "https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-cli-creating-stack.html/",
26    "https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/stacksets-concepts.html/",
27    "https://docs.aws.amazon.com/AWSCloudFormation/latest/APIReference/API_CreateStack.html/",
28    "https://docs.aws.amazon.com/AWSCloudFormation/latest/APIReference/API_CreateStackSet.html/",
29]
30risk_score = 47
31rule_id = "0415258b-a7b2-48a6-891a-3367cd9d4d31"
32severity = "medium"
33tags = [
34    "Domain: Cloud",
35    "Data Source: AWS",
36    "Data Source: Amazon Web Services",
37    "Data Source: Cloudformation",
38    "Use Case: Asset Visibility",
39    "Tactic: Execution",
40]
41timestamp_override = "event.ingested"
42type = "new_terms"
43
44query = '''
45event.dataset:aws.cloudtrail and event.provider:cloudformation.amazonaws.com and
46    event.action: (CreateStack or CreateStackSet) and event.outcome:success
47'''
48
49[[rule.threat]]
50framework = "MITRE ATT&CK"
51
52[rule.threat.tactic]
53id = "TA0002"
54name = "Execution"
55reference = "https://attack.mitre.org/tactics/TA0002/"
56
57[rule.new_terms]
58field = "new_terms_fields"
59value = ["cloud.account.id","user.name"]
60[[rule.new_terms.history_window_start]]
61field = "history_window_start"
62value = "now-10d"

References

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