Detect Local File Inclusion(LFI) in web requests (ASIM Web Session)

id: 7bb55d05-ef39-4a40-8079-0bc3c05e7881
name: Detect Local File Inclusion(LFI) in web requests (ASIM Web Session)
description: |
  'LFI vulnerabilities allow an attacker to read (and sometimes execute) files on the victim machine. This can be very dangerous because if the web server is misconfigured and running with high privileges, the attacker may gain access to sensitive information'
severity: High
status: Available 
tags:
  - Schema: WebSession
    SchemaVersion: 0.2.6
requiredDataConnectors: []
queryFrequency: 5m
queryPeriod: 5m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
  - Execution
relevantTechniques:
  - T1190
  - T1133
  - T1059
query: |
  let lookback = 5m;
  let LFI_Indicators = materialize(externaldata(Indicators: string)
      [@"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Feeds/LocalFileInclusionIndicators.csv"] 
      with(format="csv", ignoreFirstRecord=True));
  let CustomLocalFileInclusionIndicators = (_ASIM_GetWatchlistRaw("Web_LocalFileInclusionIndicators") // Create new Watchlist and add your custom indicators(Optional)
      | extend
          Indicators = tostring(WatchlistItem["Indicators"])
      | project Indicators
      | where isnotempty(Indicators));
  let CombinedLFIList = union LFI_Indicators, CustomLocalFileInclusionIndicators;
  let knownLFIIndicators=toscalar(CombinedLFIList
      | where isnotempty(Indicators)
      | summarize make_set(Indicators, 1000));
  _Im_WebSession(starttime=ago(lookback), url_has_any=knownLFIIndicators, eventresult='Success')
  | where isnotempty(Url)
  | project Url, SrcIpAddr, SrcUsername, SrcHostname, TimeGenerated
  | extend Decoded_url = url_decode(Url)
  | where Decoded_url has_any (knownLFIIndicators)
  | summarize
      EventCount=count(),
      EventStartTime=min(TimeGenerated),
      EventEndTime=max(TimeGenerated)
      by SrcIpAddr, SrcUsername, SrcHostname, Url, Decoded_url
  | extend
      Name = iif(SrcUsername contains "@", tostring(split(SrcUsername, '@', 0)[0]), SrcUsername),
      UPNSuffix = iif(SrcUsername contains "@", tostring(split(SrcUsername, '@', 1)[0]), "")
  | order by EventCount desc
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SrcIpAddr
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: Url
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: Host
    fieldMappings:
      - identifier: HostName
        columnName: SrcHostname
eventGroupingSettings:
  aggregationKind: AlertPerResult
customDetails:
  EventCount: EventCount
  Decoded_url: Decoded_url
  EventStartTime: EventStartTime
  EventEndTime: EventEndTime
alertDetailsOverride:
  alertDisplayNameFormat: "Potential Local File Inlcusion(LFI) performed by user '{{SrcUsername}}' from IP '{{SrcIpAddr}}'"
  alertDescriptionFormat: "User requested for URL '{{Url}}' which contains LFI related keywords or indicators. It suggests an attempt to traverse directories and access files outside the intended directory structure"
version: 1.0.0
kind: Scheduled