Imperva - Possible command injection

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

'Detects requests with commands in URI.'

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1133` External Remote Services `T1190` Exploit Public-Facing Application

Rule body

id: 6214f187-5840-4cf7-a174-0cf9a72bfd29
name: Imperva - Possible command injection
description: |
  'Detects requests with commands in URI.'
severity: High
status: Available
requiredDataConnectors:
  - connectorId: ImpervaWAFCloudAPI
    dataTypes:
      - ImpervaWAFCloud
queryFrequency: 10m
queryPeriod: 10m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1190
  - T1133
query: |
  let cmd_lst = dynamic(['%2fetc%2fpasswd', '%2fetc%2fshadow', 'ping', 'whoami', 'phpinfo', '%2fbin%2fbash', 'curl', 'exec(', 'wget', 'python', 'gcc' , 'uname', 'systeminfo', 'rout', 'hostname', 'ifconfig']);
  ImpervaWAFCloud
  | where QueryString has_any (cmd_lst)
  | extend IPCustomEntity = SrcIpAddr
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
version: 1.0.1
kind: Scheduled

Stages and Predicates

Let binding: `cmd_lst` used in Stage 2

let cmd_lst = dynamic(['%2fetc%2fpasswd', '%2fetc%2fshadow', 'ping', 'whoami', 'phpinfo', '%2fbin%2fbash', 'curl', 'exec(', 'wget', 'python', 'gcc' , 'uname', 'systeminfo', 'rout', 'hostname', 'ifconfig']);

Stage 1: `source`

ImpervaWAFCloud

Stage 2: `where`

| where QueryString has_any (cmd_lst)

Stage 3: `extend`

| extend IPCustomEntity = SrcIpAddr

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`QueryString`	match	`%2fbin%2fbash` transforms: `term` `%2fetc%2fpasswd` transforms: `term` `%2fetc%2fshadow` transforms: `term` `curl` transforms: `term` `exec(` transforms: `term` `gcc` transforms: `term` `hostname` transforms: `term` `ifconfig` transforms: `term` `phpinfo` transforms: `term` `ping` transforms: `term` `python` transforms: `term` `rout` transforms: `term` `systeminfo` transforms: `term` `uname` transforms: `term` `wget` transforms: `term` `whoami` transforms: `term`	`field:"QueryString" kind:match`

Output fields

These fields are emitted when the rule matches.

Field	Source
`IPCustomEntity`	`extend`

Imperva - Possible command injection

MITRE ATT&CK coverage

Rule body

Stages and Predicates

Let binding: cmd_lst used in Stage 2

Stage 1: source

Stage 2: where

Stage 3: extend

Indicators

Output fields

Let binding: `cmd_lst` used in Stage 2

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`