Detection rules › Kusto

NGINX - Put file and get file from same IP address

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

'Detects put or get files from one source in short timeframe'

MITRE ATT&CK coverage

Rule body kusto

id: e04fa38e-9fb7-438d-887a-381d5dd235e6
name: NGINX - Put file and get file from same IP address
description: |
  'Detects put or get files from one source in short timeframe' 
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: CustomLogsAma
    dataTypes:
      - NGINX_CL
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1190
  - T1133
query: |
  let p = NGINXHTTPServer
  | where HttpRequestMethod in~ ('POST', 'PUT')
  | sort by EventStartTime asc
  | summarize post_time=min(EventStartTime) by SrcIpAddr, tostring(UrlOriginal);
  NGINXHTTPServer
  | where HttpRequestMethod =~ 'GET'
  | sort by EventStartTime asc
  | summarize get_time=min(EventStartTime) by SrcIpAddr, tostring(UrlOriginal)
  | join kind=innerunique (p) on UrlOriginal, SrcIpAddr
  | extend second = datetime_diff('second',get_time,post_time)
  | where second between (1 .. 300)
  | project second, post_time, get_time, SrcIpAddr, UrlOriginal
  | extend IPCustomEntity = SrcIpAddr, UrlCustomEntity = tostring(UrlOriginal)
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: UrlCustomEntity
version: 1.0.2
kind: Scheduled

Stages and Predicates

Let binding: p

let p = NGINXHTTPServer
| where HttpRequestMethod in~ ('POST', 'PUT')
| sort by EventStartTime asc
| summarize post_time=min(EventStartTime) by SrcIpAddr, tostring(UrlOriginal);

Stage 1: source

NGINXHTTPServer

Stage 2: where

| where HttpRequestMethod =~ 'GET'

Stage 3: sort

| sort by EventStartTime asc

Stage 4: summarize

| summarize get_time=min(EventStartTime) by SrcIpAddr, tostring(UrlOriginal)

Stage 5: join

| join kind=innerunique (p) on UrlOriginal, SrcIpAddr

Stage 6: extend

| extend second = datetime_diff('second',get_time,post_time)

Stage 7: where

| where second between (1 .. 300)

Stage 8: project

| project second, post_time, get_time, SrcIpAddr, UrlOriginal

Stage 9: extend

| extend IPCustomEntity = SrcIpAddr, UrlCustomEntity = tostring(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
HttpRequestMethodeq
  • GET
HttpRequestMethodin
  • POST
  • PUT
secondge
  • 1
secondle
  • 300

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
SrcIpAddrproject
UrlOriginalproject
get_timeproject
post_timeproject
secondproject
IPCustomEntityextend
UrlCustomEntityextend