AWSCloudTrail - Suspicious command sent to EC2

Status: available
Severity: high
Time window: 1d
Source: github.com/Azure/Azure-Sentinel

An attacker with the necessary AWS permissions could be executing code remotely on an EC2 instance via SSM and saving the output to their own S3 bucket. Verify this action with the user identity and confirm it was authorized.

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1651` Cloud Administration Command

Rules detecting the same action

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

AWS Lateral Movement from Kubernetes SA via AssumeRoleWithWebIdentity (Elastic)
AWS SSM Distributed Command (Panther)
AWSCloudTrail - S3 bucket suspicious ransomware activity (Kusto)
S3 Access Via VPC Endpoint From External IP (Panther)

Rule body kusto

id: 21702832-aff3-4bd6-a8e1-663b6818503d
name: AWSCloudTrail - Suspicious command sent to EC2
description: |
  An attacker with the necessary AWS permissions could be executing code remotely on an EC2 instance via SSM and saving the output to their own S3 bucket. Verify this action with the user identity and confirm it was authorized.
severity: High
status: Available
requiredDataConnectors:
  - connectorId: AWS
    dataTypes:
      - AWSCloudTrail
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Execution
relevantTechniques:
  - T1651
query: |
    let command_executed = AWSCloudTrail
    | where EventName in ("SendCommand","CreateAssociation") and isempty(ErrorCode) and isempty(ErrorMessage)
    | extend params = tostring(parse_json(RequestParameters).parameters)
    | extend s3bucketCommand = tostring(parse_json(RequestParameters).outputS3BucketName)
    | extend s3bucketAssociation = tostring(parse_json(RequestParameters).outputLocation.s3Location.outputS3BucketName)
    | where isnotempty(params)
    | extend commandId = tostring(parse_json(ResponseElements).command.commandId)
    | extend associationId = tostring(parse_json(ResponseElements).associationDescription.associationId)
    | extend executionId = iff(isnotempty(commandId), commandId, associationId)
    | extend s3bucket = iff(isnotempty(s3bucketCommand), s3bucketCommand, s3bucketAssociation)
    | extend UserIdentityUserName = iff(isnotempty(UserIdentityUserName), UserIdentityUserName, tostring(split(UserIdentityArn,'/')[-1]));
    AWSCloudTrail
    | where EventName == "PutObject" and isempty(ErrorCode) and isempty(ErrorMessage)
    | extend s3bucket = tostring(parse_json(RequestParameters).bucketName)
    | mv-expand todynamic(Resources)
    | extend accountId=tostring(todynamic(Resources.['accountId']))
    | where Resources contains "accountId" and accountId <> RecipientAccountId
    | join command_executed on s3bucket
    | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
    | extend UserName = tostring(split(UserIdentityArn, '/')[-1])
    | extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
    | extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
      AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountName
      - identifier: UPNSuffix
        columnName: AccountUPNSuffix
      - identifier: CloudAppAccountId
        columnName: RecipientAccountId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SourceIpAddress
customDetails:
  S3Bucket: s3bucket
  ExecutionId: executionId
  AWSRegion: AWSRegion
alertDetailsOverride:
  alertDisplayNameFormat: Suspicious EC2 command execution by {{AccountName}} with output to S3 {{s3bucket}}
  alertDescriptionFormat: User {{AccountName}} sent a remote command to EC2 (execution ID {{executionId}}) with output directed to external S3 bucket {{s3bucket}}.
version: 1.0.2
kind: Scheduled

Stages and Predicates

Let binding: `command_executed`

let command_executed = AWSCloudTrail
| where EventName in ("SendCommand","CreateAssociation") and isempty(ErrorCode) and isempty(ErrorMessage)
| extend params = tostring(parse_json(RequestParameters).parameters)
| extend s3bucketCommand = tostring(parse_json(RequestParameters).outputS3BucketName)
| extend s3bucketAssociation = tostring(parse_json(RequestParameters).outputLocation.s3Location.outputS3BucketName)
| where isnotempty(params)
| extend commandId = tostring(parse_json(ResponseElements).command.commandId)
| extend associationId = tostring(parse_json(ResponseElements).associationDescription.associationId)
| extend executionId = iff(isnotempty(commandId), commandId, associationId)
| extend s3bucket = iff(isnotempty(s3bucketCommand), s3bucketCommand, s3bucketAssociation)
| extend UserIdentityUserName = iff(isnotempty(UserIdentityUserName), UserIdentityUserName, tostring(split(UserIdentityArn,'/')[-1]));

Stage 1: `source`

AWSCloudTrail

Stage 2: `where`

| where EventName == "PutObject" and isempty(ErrorCode) and isempty(ErrorMessage)

Stage 3: `extend`

| extend s3bucket = tostring(parse_json(RequestParameters).bucketName)

Stage 4: `mv-expand`

| mv-expand todynamic(Resources)

Stage 5: `extend`

| extend accountId=tostring(todynamic(Resources.['accountId']))

Stage 6: `where`

| where Resources contains "accountId" and accountId <> RecipientAccountId

Stage 7: `join`

| join command_executed on s3bucket

Stage 8: `extend` (4 consecutive steps)

| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
| extend UserName = tostring(split(UserIdentityArn, '/')[-1])
| extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
| extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
  AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")

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`	is_null	(no value, null check)
`ErrorMessage`	is_null	(no value, null check)
`EventName`	eq	`PutObject` transforms: `cased`
`EventName`	in	`CreateAssociation` transforms: `cased` `SendCommand` transforms: `cased`
`Resources`	contains	`accountId`
`accountId`	ne	`RecipientAccountId` transforms: `cased`
`params`	is_not_null	(no value, null check)

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
`s3bucket`	`extend`
`accountId`	`extend`
`UserIdentityArn`	`extend`
`UserName`	`extend`
`AccountName`	`extend`
`AccountUPNSuffix`	`extend`

`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)

AWSCloudTrail - Suspicious command sent to EC2

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Let binding: `command_executed`

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `mv-expand`

Stage 5: `extend`

Stage 6: `where`

Stage 7: `join`

Stage 8: `extend` (4 consecutive steps)

Indicators

Output fields

Keyboard shortcuts

Search operators

AWSCloudTrail - Suspicious command sent to EC2

MITRE ATT&CK coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Let binding: command_executed

Stage 1: source

Stage 2: where

Stage 3: extend

Stage 4: mv-expand

Stage 5: extend

Stage 6: where

Stage 7: join

Stage 8: extend (4 consecutive steps)

Indicators

Output fields

Let binding: `command_executed`

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `mv-expand`

Stage 5: `extend`

Stage 6: `where`

Stage 7: `join`

Stage 8: `extend` (4 consecutive steps)