IAM User Creation Attempt

Status: test
Severity: medium
Log source: product aws, service cloudtrail
Author: nishikawaakira (@nishikawaakira)
Source: github.com/Yamato-Security/suzaku-rules

Detects a failed attempt to create an IAM user (AccessDenied). Even though the attempt failed, it indicates the attacker has valid credentials and is attempting persistence via IAM user creation.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1136.003` Create Account: Cloud Account

Event coverage

Provider	Event
AWS-iam	CreateUser

Rules detecting the same action

Other rules on this platform that filter on the same API call or operation.

AWS IAM Create User via Assumed Role on EC2 Instance (Elastic)
AWS IAM S3Browser User or AccessKey Creation (Sigma)
AWS IAM Sensitive Operations via Lambda Execution Role (Elastic)
AWS Sensitive IAM Operations Performed via CloudShell (Elastic)
High-Risk Cross-Cloud User Impersonation (Kusto)
IAM User Created (Sigma)

Rule body yaml

title: IAM User Creation Attempt
id: 8f3a7b2c-1d4e-5f6a-9b0c-2e3d4f5a6b7d
status: test
description: |
    Detects a failed attempt to create an IAM user (AccessDenied).
    Even though the attempt failed, it indicates the attacker has valid
    credentials and is attempting persistence via IAM user creation.
references:
    - https://attack.mitre.org/techniques/T1136/003/
    - https://docs.aws.amazon.com/IAM/latest/APIReference/API_CreateUser.html
author: nishikawaakira (@nishikawaakira)
date: 2026-05-03
modified: 2026-05-29
tags:
    - attack.persistence
    - attack.t1136.003
logsource:
    product: aws
    service: cloudtrail
detection:
    selection:
        eventSource: iam.amazonaws.com
        eventName: CreateUser
        errorCode: AccessDenied
    condition: selection
falsepositives:
level: medium

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    eventSource: iam.amazonaws.com
    eventName: CreateUser
    errorCode: AccessDenied

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`errorCode`	eq	`AccessDenied`
`eventName`	eq	`CreateUser`
`eventSource`	eq	`iam.amazonaws.com`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

IAM User Creation Attempt

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection`

Indicators

Keyboard shortcuts

Search operators

IAM User Creation Attempt

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection

Indicators

Stage 0: `condition`

Stage 1: `selection`