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

Status: available
Severity: high
Time window: 5m
Group by: Decoded_url, SrcHostname, SrcIpAddr, SrcUsername, Url
Source: github.com/Azure/Azure-Sentinel

'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'

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1133` External Remote Services, `T1190` Exploit Public-Facing Application
Execution	`T1059` Command and Scripting Interpreter

Rule body kusto

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

Stages and Predicates

Parameters

let lookback = 5m;
let CombinedLFIList = union LFI_Indicators, CustomLocalFileInclusionIndicators;

Let binding: `LFI_Indicators`

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 binding: `CustomLocalFileInclusionIndicators`

let CustomLocalFileInclusionIndicators = (_ASIM_GetWatchlistRaw("Web_LocalFileInclusionIndicators")
    | extend
        Indicators = tostring(WatchlistItem["Indicators"])
    | project Indicators
    | where isnotempty(Indicators));

Let binding: `knownLFIIndicators`

let knownLFIIndicators = toscalar(CombinedLFIList
    | where isnotempty(Indicators)
    | summarize make_set(Indicators, 1000));

Derived from CombinedLFIList.

Stage 1: `source`

_Im_WebSession(starttime=ago(lookback), url_has_any=knownLFIIndicators, eventresult='Success')

Stage 2: `where`

| where isnotempty(Url)

Stage 3: `project`

| project Url, SrcIpAddr, SrcUsername, SrcHostname, TimeGenerated

Stage 4: `extend`

| extend Decoded_url = url_decode(Url)

Stage 5: `where`

| where Decoded_url has_any (knownLFIIndicators)

References knownLFIIndicators (defined above).

Stage 6: `summarize`

| summarize
    EventCount=count(),
    EventStartTime=min(TimeGenerated),
    EventEndTime=max(TimeGenerated)
    by SrcIpAddr, SrcUsername, SrcHostname, Url, Decoded_url

Stage 7: `extend`

| extend
    Name = iif(SrcUsername contains "@", tostring(split(SrcUsername, '@', 0)[0]), SrcUsername),
    UPNSuffix = iif(SrcUsername contains "@", tostring(split(SrcUsername, '@', 1)[0]), "")

Stage 8: `sort`

| order by EventCount desc

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.

Field	Kind	Values
`Decoded_url`	match	`knownLFIIndicators`
`Url`	is_not_null	(no value, null check)

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.

Field	Source
`Decoded_url`	`summarize`
`EventCount`	`summarize`
`EventEndTime`	`summarize`
`EventStartTime`	`summarize`
`SrcHostname`	`summarize`
`SrcIpAddr`	`summarize`
`SrcUsername`	`summarize`
`Url`	`summarize`
`Name`	`extend`
`UPNSuffix`	`extend`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

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

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: `LFI_Indicators`

Let binding: `CustomLocalFileInclusionIndicators`

Let binding: `knownLFIIndicators`

Stage 1: `source`

Stage 2: `where`

Stage 3: `project`

Stage 4: `extend`

Stage 5: `where`

Stage 6: `summarize`

Stage 7: `extend`

Stage 8: `sort`

Indicators

Output fields

Keyboard shortcuts

Search operators

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

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: LFI_Indicators

Let binding: CustomLocalFileInclusionIndicators

Let binding: knownLFIIndicators

Stage 1: source

Stage 2: where

Stage 3: project

Stage 4: extend

Stage 5: where

Stage 6: summarize

Stage 7: extend

Stage 8: sort

Indicators

Output fields

Let binding: `LFI_Indicators`

Let binding: `CustomLocalFileInclusionIndicators`

Let binding: `knownLFIIndicators`

Stage 1: `source`

Stage 2: `where`

Stage 3: `project`

Stage 4: `extend`

Stage 5: `where`

Stage 6: `summarize`

Stage 7: `extend`

Stage 8: `sort`