Application Gateway WAF - SQLi Detection

Severity: high
Time window: 6h
Group by: SQLI_Score, TotalInboundScore, Uri, action_s, clientIp_s, transactionId_g
Author: shabaz-github
Source: github.com/Azure/Azure-Sentinel

'Identifies a match for SQL Injection attack in the Application gateway WAF logs. The Threshold value in the query can be changed as per your infrastructure's requirement. References: https://owasp.org/Top10/A03_2021-Injection/'

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1190` Exploit Public-Facing Application
Execution	`T1059` Command and Scripting Interpreter
Stealth	`T1211` Exploitation for Stealth
Privilege Escalation	`T0890` Exploitation for Privilege Escalation

Rules detecting the same action

These rules filter on the same operation.

Application Gateway WAF - XSS Detection (Kusto)
Azure WAF matching for Log4j vuln(CVE-2021-44228) (Kusto)
User agent search for log4j exploitation attempt (Kusto)

Rule body

id: 68c0b6bb-6bd9-4ef4-9011-08998c8ef90f
name: Application Gateway WAF - SQLi Detection  
description: | 
  'Identifies a match for SQL Injection attack in the Application gateway WAF logs. The Threshold value in the query can be changed as per your infrastructure's requirement.
   References: https://owasp.org/Top10/A03_2021-Injection/'
severity: High 
requiredDataConnectors: 
  - connectorId: WAF
    dataTypes: 
      - AzureDiagnostics
queryFrequency: 6h 
queryPeriod: 6h 
triggerOperator: gt 
triggerThreshold: 0 
tactics: 
  - DefenseEvasion
  - Execution
  - InitialAccess
  - PrivilegeEscalation 
relevantTechniques:
  - T1211
  - T1059
  - T1190
  - T0890
tags:
  - SQL Injection
query:  |  
  let Threshold = 3;
  AzureDiagnostics
  | where Category == "ApplicationGatewayFirewallLog"
  | where action_s == "Matched"
  | project transactionId_g, hostname_s, requestUri_s, TimeGenerated, clientIp_s, Message, details_message_s, details_data_s
  | join kind = inner(
  AzureDiagnostics
  | where Category == "ApplicationGatewayFirewallLog"
  | where action_s == "Blocked"
  | parse Message with MessageText 'Total Inbound Score: ' TotalInboundScore ' - SQLI=' SQLI_Score ',XSS=' XSS_Score ',RFI=' RFI_Score ',LFI=' LFI_Score ',RCE=' RCE_Score ',PHPI=' PHPI_Score ',HTTP=' HTTP_Score ',SESS=' SESS_Score '): ' Blocked_Reason '; individual paranoia level scores:' Paranoia_Score
  | where Blocked_Reason contains "SQL Injection Attack" and toint(SQLI_Score) >=10 and toint(TotalInboundScore) >= 15) on transactionId_g
  | extend Uri = strcat(hostname_s,requestUri_s)
  | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), TransactionID = make_set(transactionId_g), Message = make_set(Message), Detail_Message = make_set(details_message_s), Detail_Data = make_set(details_data_s), Total_TransactionId = dcount(transactionId_g) by clientIp_s, Uri, action_s, SQLI_Score, TotalInboundScore
  | where Total_TransactionId >= Threshold
# The Threshold value above can be changed as per your infrastructure's requirement 
entityMappings:
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: Uri
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: clientIp_s 
version: 1.0.1
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: shabaz-github
    support:
        tier: Community
    categories:
        domains: [ "Security - Threat Protection", "Platform" ]

Stages and Predicates

Parameters

let Threshold = 3;

Stage 1: `source`

AzureDiagnostics

Stage 2: `where`

| where Category == "ApplicationGatewayFirewallLog"

Stage 3: `where`

| where action_s == "Matched"

Stage 4: `project`

| project transactionId_g, hostname_s, requestUri_s, TimeGenerated, clientIp_s, Message, details_message_s, details_data_s

Stage 5: `join`

| join kind = inner(
AzureDiagnostics
| where Category == "ApplicationGatewayFirewallLog"
| where action_s == "Blocked"
| parse Message with MessageText 'Total Inbound Score: ' TotalInboundScore ' - SQLI=' SQLI_Score ',XSS=' XSS_Score ',RFI=' RFI_Score ',LFI=' LFI_Score ',RCE=' RCE_Score ',PHPI=' PHPI_Score ',HTTP=' HTTP_Score ',SESS=' SESS_Score '): ' Blocked_Reason '; individual paranoia level scores:' Paranoia_Score
| where Blocked_Reason contains "SQL Injection Attack" and toint(SQLI_Score) >=10 and toint(TotalInboundScore) >= 15) on transactionId_g

Stage 6: `extend`

| extend Uri = strcat(hostname_s,requestUri_s)

Stage 7: `summarize`

| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), TransactionID = make_set(transactionId_g), Message = make_set(Message), Detail_Message = make_set(details_message_s), Detail_Data = make_set(details_data_s), Total_TransactionId = dcount(transactionId_g) by clientIp_s, Uri, action_s, SQLI_Score, TotalInboundScore

Stage 8: `where`

| where Total_TransactionId >= Threshold

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Blocked_Reason`	contains	`SQL Injection Attack`	`field:"Blocked_Reason" kind:contains value:"SQL Injection Attack"`
`Category`	eq	`ApplicationGatewayFirewallLog`	`field:"Category" kind:eq value:"ApplicationGatewayFirewallLog"`
`SQLI_Score`	ge	`10` transforms: `toint`	`field:"SQLI_Score" kind:ge value:"10"`
`TotalInboundScore`	ge	`15` transforms: `toint`	`field:"TotalInboundScore" kind:ge value:"15"`
`Total_TransactionId`	ge	`3`	`field:"Total_TransactionId" kind:ge value:"3"`
`action_s`	eq	`Blocked` `Matched`	`field:"action_s" kind:eq`

Output fields

These fields are emitted when the rule matches.

Field	Source
`Detail_Data`	`summarize`
`Detail_Message`	`summarize`
`EndTime`	`summarize`
`Message`	`summarize`
`SQLI_Score`	`summarize`
`StartTime`	`summarize`
`TotalInboundScore`	`summarize`
`Total_TransactionId`	`summarize`
`TransactionID`	`summarize`
`Uri`	`summarize`
`action_s`	`summarize`
`clientIp_s`	`summarize`

Application Gateway WAF - SQLi Detection

MITRE ATT&CK coverage

Rules detecting the same action

Rule body

Stages and Predicates

Parameters

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: project

Stage 5: join

Stage 6: extend

Stage 7: summarize

Stage 8: where