F&O - Bank account change following network alias reassignment

Status: available
Severity: low
Time window: 1d
Group by: UserId, Username
Source: github.com/Azure/Azure-Sentinel

Identifies changes to user accounts where the network alias was modified to a new value. Shortly afterwards, the updated alias is used to update a bank account number.

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1078` Valid Accounts
Credential Access	`T1556` Modify Authentication Process
Persistence	`T0859` Valid Accounts
Lateral Movement	`T0859` Valid Accounts

Rule body kusto

id: dccbdb5b-2ce7-4931-bfbe-f1ad6523ee64
kind: Scheduled
name: F&O - Bank account change following network alias reassignment
description: Identifies changes to user accounts where the network alias was modified
  to a new value. Shortly afterwards, the updated alias is used to update a bank account
  number.
severity: Low
status: Available
requiredDataConnectors:
  - connectorId: Dynamics365Finance
    dataTypes:
      - FinanceOperationsActivity_CL
queryFrequency: 15m
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CredentialAccess
  - LateralMovement
  - PrivilegeEscalation
relevantTechniques:
  - T1556
  - T0859
  - T1078
query: |
  let query_frequency = 15m;
  FinanceOperationsActivity_CL
  | where LogType == "Update" and TableName == "UserInfo"
  | extend UserId = tostring(parse_json(tostring(FormattedData.["03::id"])).NewData)
  | extend NetworkAlias = parse_json(tostring(FormattedData.networkAlias))
  | extend
      CurrentAlias = tostring(NetworkAlias.NewData),
      PreviousAlias = tostring(NetworkAlias.OldData)
  | where CurrentAlias != PreviousAlias
  | extend
      AliasUpdated = LogCreatedDateTime,
      AliasChangedBy = Username
  | join kind=inner(FinanceOperationsActivity_CL
      | where TimeGenerated >= ago (query_frequency)
      | where LogType == "Update" and TableName == "BankAccountTable"
      | extend AccountId = tostring(parse_json(tostring(FormattedData.AccountID)).NewData)
      | extend AccountNum = parse_json(tostring(FormattedData.AccountNum))
      | extend
          CurrentAccountNum = tostring(AccountNum.NewData),
          OldAccountNum = tostring(AccountNum.OldData)
      | where CurrentAccountNum != OldAccountNum
      | extend BankUpdated = LogCreatedDateTime)
      on $left.UserId == $right.Username
  | where BankUpdated > AliasUpdated
  | extend
      FinOpsAppId = 32780,
      AccountName = tostring(split(CurrentAlias, "@")[0]),
      UPNSuffix = tostring(split(CurrentAlias, "@")[1])
  | project
      AliasUpdated,
      AliasChangedBy,
      Username,
      AccountId,
      CurrentAccountNum,
      OldAccountNum,
      CurrentAlias,
      PreviousAlias,
      FinOpsAppId,
      AccountName,
      UPNSuffix
eventGroupingSettings:
  aggregationKind: SingleAlert
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: AliasChangedBy
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountName
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: Username
alertDetailsOverride:
  alertDisplayNameFormat: F&O - Suspicious bank account changes
  alertDescriptionFormat: A user account alias was reassigned for {{Username}} by
    {{AliasChangedBy}} and shortly afterwards, bank account {{AccountId}} was modified.
version: 3.2.0

Stages and Predicates

Parameters

let query_frequency = 15m;

Stage 1: `source`

FinanceOperationsActivity_CL

Stage 2: `where`

| where LogType == "Update" and TableName == "UserInfo"

Stage 3: `extend` (3 consecutive steps)

| extend UserId = tostring(parse_json(tostring(FormattedData.["03::id"])).NewData)
| extend NetworkAlias = parse_json(tostring(FormattedData.networkAlias))
| extend
    CurrentAlias = tostring(NetworkAlias.NewData),
    PreviousAlias = tostring(NetworkAlias.OldData)

Stage 4: `where`

| where CurrentAlias != PreviousAlias

Stage 5: `extend`

| extend
    AliasUpdated = LogCreatedDateTime,
    AliasChangedBy = Username

Stage 6: `join`

| join kind=inner(FinanceOperationsActivity_CL
    | where TimeGenerated >= ago (query_frequency)
    | where LogType == "Update" and TableName == "BankAccountTable"
    | extend AccountId = tostring(parse_json(tostring(FormattedData.AccountID)).NewData)
    | extend AccountNum = parse_json(tostring(FormattedData.AccountNum))
    | extend
        CurrentAccountNum = tostring(AccountNum.NewData),
        OldAccountNum = tostring(AccountNum.OldData)
    | where CurrentAccountNum != OldAccountNum
    | extend BankUpdated = LogCreatedDateTime)
    on $left.UserId == $right.Username

Stage 7: `where`

| where BankUpdated > AliasUpdated

Stage 8: `extend`

| extend
    FinOpsAppId = 32780,
    AccountName = tostring(split(CurrentAlias, "@")[0]),
    UPNSuffix = tostring(split(CurrentAlias, "@")[1])

Stage 9: `project`

| project
    AliasUpdated,
    AliasChangedBy,
    Username,
    AccountId,
    CurrentAccountNum,
    OldAccountNum,
    CurrentAlias,
    PreviousAlias,
    FinOpsAppId,
    AccountName,
    UPNSuffix

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
`BankUpdated`	gt	`AliasUpdated` transforms: `cased`
`CurrentAccountNum`	ne	`OldAccountNum` transforms: `cased`
`CurrentAlias`	ne	`PreviousAlias` transforms: `cased`
`LogType`	eq	`Update` transforms: `cased`
`TableName`	eq	`BankAccountTable` transforms: `cased` `UserInfo` transforms: `cased`

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
`AccountId`	`project`
`AccountName`	`project`
`AliasChangedBy`	`project`
`AliasUpdated`	`project`
`CurrentAccountNum`	`project`
`CurrentAlias`	`project`
`FinOpsAppId`	`project`
`OldAccountNum`	`project`
`PreviousAlias`	`project`
`UPNSuffix`	`project`
`Username`	`project`

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`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)

F&O - Bank account change following network alias reassignment

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend` (3 consecutive steps)

Stage 4: `where`

Stage 5: `extend`

Stage 6: `join`

Stage 7: `where`

Stage 8: `extend`

Stage 9: `project`

Indicators

Output fields

Keyboard shortcuts

Search operators

F&O - Bank account change following network alias reassignment

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: source

Stage 2: where

Stage 3: extend (3 consecutive steps)

Stage 4: where

Stage 5: extend

Stage 6: join

Stage 7: where

Stage 8: extend

Stage 9: project

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend` (3 consecutive steps)

Stage 4: `where`

Stage 5: `extend`

Stage 6: `join`

Stage 7: `where`

Stage 8: `extend`

Stage 9: `project`