AWS Unsuccessful MFA attempt

Severity: high
Log types: AWS.CloudTrail
Tags: Configuration Required
Reference: https://attack.mitre.org/techniques/T1621/
Source: github.com/panther-labs/panther-analysis

Monitor application logs for suspicious events including repeated MFA failures that may indicate user's primary credentials have been compromised.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1621` Multi-Factor Authentication Request Generation

Rule body yaml

AnalysisType: rule
Description: Monitor application logs for suspicious events including repeated MFA failures that may indicate user's primary credentials have been compromised.
DisplayName: "AWS Unsuccessful MFA attempt"
Enabled: false
Filename: aws_cloudtrail_unsuccessful_mfa_attempt.py
Reference: https://attack.mitre.org/techniques/T1621/
Tags:
  - Configuration Required # configure threshold for multiple MFA failures
Reports:
  MITRE ATT&CK:
    - TA0006:T1621
Severity: High
Tests:
  - ExpectedResult: false
    Log:
      additionalEventData:
        LoginTo: https://console.aws.amazon.com/console/home?state=hashArgs%23&isauthcode=true
        MFAIdentifier: arn:aws:iam::111122223333:u2f/user/anaya/default-AAAAAAAABBBBBBBBCCCCCCCCDD
        MFAUsed: "Yes"
        MobileVersion: "No"
      awsRegion: us-east-1
      eventID: fed06f42-cb12-4764-8c69-121063dc79b9
      eventName: ConsoleLogin
      eventSource: signin.amazonaws.com
      eventTime: "2022-11-10T16:24:34Z"
      eventType: AwsConsoleSignIn
      eventVersion: "1.05"
      recipientAccountId: "111122223333"
      requestParameters: null
      responseElements:
        ConsoleLogin: Success
      sourceIPAddress: 192.0.2.0
      userAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36
      userIdentity:
        accountId: "111122223333"
        arn: arn:aws:iam::111122223333:user/anaya
        principalId: AIDACKCEVSQ6C2EXAMPLE
        type: IAMUser
        userName: anaya
    Name: Successful Login w/ MFA
  - ExpectedResult: true
    Log:
      additionalEventData:
        LoginTo: https://console.aws.amazon.com/console/home?state=hashArgs%23&isauthcode=true
        MFAUsed: "Yes"
        MobileVersion: "No"
      awsRegion: us-east-1
      errorMessage: Failed authentication
      eventID: d38ce1b3-4575-4cb8-a632-611b8243bfc3
      eventName: ConsoleLogin
      eventSource: signin.amazonaws.com
      eventTime: "2022-11-10T16:24:34Z"
      eventType: AwsConsoleSignIn
      eventVersion: "1.05"
      recipientAccountId: "111122223333"
      requestParameters: null
      responseElements:
        ConsoleLogin: Failure
      sourceIPAddress: 192.0.2.0
      userAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36
      userIdentity:
        accessKeyId: ""
        accountId: "111122223333"
        principalId: AIDACKCEVSQ6C2EXAMPLE
        type: IAMUser
        userName: anaya
    Name: Unsuccessful Login w/ MFA
DedupPeriodMinutes: 15
LogTypes:
  - AWS.CloudTrail
RuleID: "AWS.Unsuccessful.MFA.attempt"
Threshold: 2

Detection logic

Condition

not (eventSource ne "signin.amazonaws.com" and eventName ne "ConsoleLogin")
additionalEventData.MFAUsed eq "Yes"
responseElements.ConsoleLogin eq "Failure"

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`eventName`	ne	`ConsoleLogin`
`eventSource`	ne	`signin.amazonaws.com`

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
`additionalEventData.MFAUsed`	eq	`Yes`
`responseElements.ConsoleLogin`	eq	`Failure`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`eventName`
`eventSource`
`awsRegion`
`recipientAccountId`
`sourceIPAddress`
`userAgent`
`userIdentity`
`arn`	`userIdenity.arn`
`userName`	`userIdentity.userName`

`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)