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Detection rules › Kusto

NGINX - Command in URI

Status
available
Severity
high
Time window
10m
Source
github.com/Azure/Azure-Sentinel

'Detects command in URI'

MITRE ATT&CK coverage

TacticTechniques
Initial Access

Rule body

id: d84739ce-2f46-4391-b25e-a2edbea19d7e
name: NGINX - Command in URI
description: |
  'Detects command in URI'
severity: High
status: Available
requiredDataConnectors:
  - connectorId: CustomLogsAma
    dataTypes:
      - NGINX_CL
queryFrequency: 10m
queryPeriod: 10m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1190
  - T1133
query: |
  let cmd_list = dynamic(['cat%20/etc/passwd', '/etc/passwd', 'ping -i', '/usr/bin/id(', '%2f%75%73%72%2f%62%69%6e%2f%69%64', 'phpinfo()', '%70%68%70%69%6e%66%6f%28%29', ';id', '%3b%69%64', '/bin/bash -c', '%2f%62%69%6e%2f%62%61%73%68%20%2d%63%27', '/bin/bash', '%2f%62%69%6e%2f%62%61%73%68', 'sleep(', '%73%6c%65%65%70%28', 'curl', '%63%75%72%6c', '&dir', '%26%64%69%72', '& dir', '%26%20%64%69%72', '<script>', '%3c%73%63%72%69%70%74%3e', 'eval(', '%65%76%61%6c%28', 'exec(', '%65%78%65%63%28', 'whoami', '%77%68%6f%61%6d%69', 'wget', 'python', 'gcc', 'uname', 'systeminfo', '%77%67%65%74', '%70%79%74%68%6f%6e', '%75%6e%61%6d%65', '%73%79%73%74%65%6d%69%6e%66%6f']);
  NGINXHTTPServer
  | where UrlOriginal has_any (cmd_list)
  | extend UrlCustomEntity = UrlOriginal
entityMappings:
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: UrlCustomEntity
version: 1.0.3
kind: Scheduled

Stages and Predicates

Let binding: cmd_list used in Stage 2

let cmd_list = dynamic(['cat%20/etc/passwd', '/etc/passwd', 'ping -i', '/usr/bin/id(', '%2f%75%73%72%2f%62%69%6e%2f%69%64', 'phpinfo()', '%70%68%70%69%6e%66%6f%28%29', ';id', '%3b%69%64', '/bin/bash -c', '%2f%62%69%6e%2f%62%61%73%68%20%2d%63%27', '/bin/bash', '%2f%62%69%6e%2f%62%61%73%68', 'sleep(', '%73%6c%65%65%70%28', 'curl', '%63%75%72%6c', '&dir', '%26%64%69%72', '& dir', '%26%20%64%69%72', '<script>', '%3c%73%63%72%69%70%74%3e', 'eval(', '%65%76%61%6c%28', 'exec(', '%65%78%65%63%28', 'whoami', '%77%68%6f%61%6d%69', 'wget', 'python', 'gcc', 'uname', 'systeminfo', '%77%67%65%74', '%70%79%74%68%6f%6e', '%75%6e%61%6d%65', '%73%79%73%74%65%6d%69%6e%66%6f']);

Stage 1: source

NGINXHTTPServer

Stage 2: where

| where UrlOriginal has_any (cmd_list)

Stage 3: extend

| extend UrlCustomEntity = UrlOriginal

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
UrlOriginalmatch
  • %26%20%64%69%72 transforms: term
  • %26%64%69%72 transforms: term
  • %2f%62%69%6e%2f%62%61%73%68 transforms: term
  • %2f%62%69%6e%2f%62%61%73%68%20%2d%63%27 transforms: term
  • %2f%75%73%72%2f%62%69%6e%2f%69%64 transforms: term
  • %3b%69%64 transforms: term
  • %3c%73%63%72%69%70%74%3e transforms: term
  • %63%75%72%6c transforms: term
  • %65%76%61%6c%28 transforms: term
  • %65%78%65%63%28 transforms: term
  • %70%68%70%69%6e%66%6f%28%29 transforms: term
  • %70%79%74%68%6f%6e transforms: term
  • %73%6c%65%65%70%28 transforms: term
  • %73%79%73%74%65%6d%69%6e%66%6f transforms: term
  • %75%6e%61%6d%65 transforms: term
  • %77%67%65%74 transforms: term
  • %77%68%6f%61%6d%69 transforms: term
  • & dir transforms: term
  • &dir transforms: term
  • /bin/bash transforms: term
  • /bin/bash -c transforms: term
  • /etc/passwd transforms: term
  • /usr/bin/id( transforms: term
  • ;id transforms: term
  • <script> transforms: term
  • cat%20/etc/passwd transforms: term
  • curl transforms: term
  • eval( transforms: term
  • exec( transforms: term
  • gcc transforms: term
  • phpinfo() transforms: term
  • ping -i transforms: term
  • python transforms: term
  • sleep( transforms: term
  • systeminfo transforms: term
  • uname transforms: term
  • wget transforms: term
  • whoami transforms: term
field:"UrlOriginal" kind:match

Output fields

These fields are emitted when the rule matches.

FieldSource
UrlCustomEntityextend