Potential Sidecar Injection Into Running Deployment

Status: test
Severity: medium
Log source: product kubernetes, category application, service audit
Author: Leo Tsaousis (@laripping)
Source: github.com/SigmaHQ/sigma

Detects attempts to inject a sidecar container into a running deployment. A sidecar container is an additional container within a pod, that resides alongside the main container. One way to add containers to running resources like Deployments/DeamonSets/StatefulSets, is via a "kubectl patch" operation. By injecting a new container within a legitimate pod, an attacker can run their code and hide their activity, instead of running their own separated pod in the cluster.

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1609` Container Administration Command

Event coverage

Provider	Event	Title
Kubernetes-deployments	patch-deployments	patch deployments

Rules detecting the same action

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

Kubernetes Sensitive RBAC Change Followed by Workload Modification (Elastic)
Unusual Kubernetes Sensitive Workload Modification (Elastic)

Rule body yaml

title: Potential Sidecar Injection Into Running Deployment
id: ad9012a6-e518-4432-9890-f3b82b8fc71f
status: test
description: |
    Detects attempts to inject a sidecar container into a running deployment.
    A sidecar container is an additional container within a pod, that resides alongside the main container.
    One way to add containers to running resources like Deployments/DeamonSets/StatefulSets, is via a "kubectl patch" operation.
    By injecting a new container within a legitimate pod, an attacker can run their code and hide their activity, instead of running their own separated pod in the cluster.
references:
    - https://kubernetes.io/docs/tasks/manage-kubernetes-objects/update-api-object-kubectl-patch
    - https://microsoft.github.io/Threat-Matrix-for-Kubernetes/techniques/Sidecar%20Injection/
author: Leo Tsaousis (@laripping)
date: 2024-03-26
tags:
    - attack.t1609
    - attack.execution
logsource:
    category: application
    product: kubernetes
    service: audit
detection:
    selection:
        verb: 'patch'
        apiGroup: 'apps'
        objectRef.resource: 'deployments'
    condition: selection
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    verb: 'patch'
    apiGroup: 'apps'
    objectRef.resource: 'deployments'

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
`apiGroup`	eq	`apps`
`objectRef.resource`	eq	`deployments`
`verb`	eq	`patch`

`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)

Potential Sidecar Injection Into Running Deployment

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

Potential Sidecar Injection Into Running Deployment

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`