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Detection rules › Kusto

Apache - Put suspicious file

Status
available
Severity
medium
Time window
1h
Source
github.com/Azure/Azure-Sentinel

'Detects PUT or POST of suspicious file'

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1133 External Remote Services, T1190 Exploit Public-Facing Application
ExfiltrationT1048 Exfiltration Over Alternative Protocol

Rule body kusto

id: c5d69e46-3b00-11ec-8d3d-0242ac130003
name: Apache - Put suspicious file
description: |
  'Detects PUT or POST of suspicious file'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: CustomLogsAma
    datatypes:
      - ApacheHTTPServer_CL
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
  - Exfiltration
relevantTechniques:
  - T1190
  - T1133
  - T1048
query: |
  ApacheHTTPServer
  | where HttpRequestMethod in~ ("POST", "PUT") 
  | extend File = extract(@"(.*\/)?(.*)", 2, tostring(UrlOriginal))
  | where isnotempty(File)
  | where File matches regex @"([a-zA-Z0-9-_]+\.)([a-zA-Z0-9-]+\.[a-zA-Z0-9-]+)"
  | extend FileCustomEntity = File, UrlCustomEntity = UrlOriginal
entityMappings:
  - entityType: File
    fieldMappings:
      - identifier: Name
        columnName: FileCustomEntity
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: UrlCustomEntity
version: 1.0.2
kind: Scheduled

Stages and Predicates

Stage 1: source

ApacheHTTPServer

Stage 2: where

| where HttpRequestMethod in~ ("POST", "PUT")

Stage 3: extend

| extend File = extract(@"(.*\/)?(.*)", 2, tostring(UrlOriginal))

Stage 4: where

| where isnotempty(File)

Stage 5: where

| where File matches regex @"([a-zA-Z0-9-_]+\.)([a-zA-Z0-9-]+\.[a-zA-Z0-9-]+)"

Stage 6: extend

| extend FileCustomEntity = File, UrlCustomEntity = UrlOriginal

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.

FieldKindValues
Fileis_not_null
  • (no value, null check)
Fileregex_match
  • ([a-zA-Z0-9-_]+.)([a-zA-Z0-9-]+.[a-zA-Z0-9-]+)
HttpRequestMethodin
  • POST
  • PUT

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.

FieldSource
Fileextend
FileCustomEntityextend
UrlCustomEntityextend