High severity malicious activity detected

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Id	504257c1-81e2-4609-8d40-b395e62f11c7
Rulename	High severity malicious activity detected
Description	Identifies high severity malicious activity in Azure Firewall IDPS logs.
Severity	High
Tactics	InitialAccess Exfiltration CredentialAccess CommandAndControl Execution
Techniques	T1190 T1041 T1003 T1204
Required data connectors	AzureFirewall
Kind	Scheduled
Query frequency	1h
Query period	24h
Trigger threshold	1
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Firewall/Analytic Rules/Azure Firewall - High severity malicious activity detected.yaml
Version	1.0.0
Arm template	504257c1-81e2-4609-8d40-b395e62f11c7.json

KQL

let TimeWindow   = 90d;    // How far back to look 
let HitThreshold = 10;     // Minimum hits to alert per SourceIp + Category
let MinSeverity  = 1;      // Set Minimum Severity
let EnableCategoryFilter    = true;   // Filter 1: use CategoriesOfInterest
let EnableDescriptionFilter = false;  // Filter 2: use DescriptionsOfInterest
let EnableActionFilter      = false;  // Filter 3: use MatchActions
let CategoriesOfInterest    = dynamic([
    "Targeted Malicious Activity was Detected",
    "Exploit Kit Activity Detected",
    "Domain Observed Used for C2 Detected",
    "Successful Credential Theft Detected",
    "Malware Command and Control Activity Detected",
    "Executable code was detected",
    "A Network Trojan was detected"
]);
let DescriptionsOfInterest  = dynamic([
    "targeted-activity",
    "exploit-kit",
    "domain-c2",
    "credential-theft",
    "command-and-control",
    "shellcode-detect",
    "trojan-activity"
]);
let MatchActions = dynamic(["Deny", "alert"]);
AZFWIdpsSignature
| where TimeGenerated >= ago(TimeWindow)
| where Severity >= MinSeverity
// Filter 1: Category filter (optional)
| where (EnableCategoryFilter == false) or (Category has_any (CategoriesOfInterest))
// Filter 2: Description filter (optional)
| where (EnableDescriptionFilter == false) or (Description has_any (DescriptionsOfInterest))
// Filter 3: Action filter (optional)
| where (EnableActionFilter == false) or (Action in~ (MatchActions))
| summarize
    StartTime   = min(TimeGenerated),
    EndTime     = max(TimeGenerated),
    TotalHits   = count(),
    MaxSeverity = max(Severity),
    Actions     = make_set(Action, 5),
    Signatures  = make_set(SignatureId, 20),
    Description = make_set(substring(tostring(Description), 0, 120), 3)
    by SourceIp, ThreatCategory = Category
| where TotalHits >= HitThreshold
| project
    StartTime,
    EndTime,
    SourceIp,
    ThreatCategory,
    TotalHits,
    MaxSeverity,
    Actions,
    Signatures,
    Description
| order by MaxSeverity desc, TotalHits desc

YAML

name: High severity malicious activity detected
relevantTechniques:
- T1190
- T1041
- T1003
- T1204
id: 504257c1-81e2-4609-8d40-b395e62f11c7
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Firewall/Analytic Rules/Azure Firewall - High severity malicious activity detected.yaml
requiredDataConnectors:
- dataTypes:
  - AZFWIdpsSignature
  connectorId: AzureFirewall
version: 1.0.0
severity: High
triggerThreshold: 1
queryPeriod: 24h
entityMappings:
- fieldMappings:
  - identifier: Address
    columnName: SourceIp
  entityType: IP
queryFrequency: 1h
status: Available
query: |
  let TimeWindow   = 90d;    // How far back to look 
  let HitThreshold = 10;     // Minimum hits to alert per SourceIp + Category
  let MinSeverity  = 1;      // Set Minimum Severity
  let EnableCategoryFilter    = true;   // Filter 1: use CategoriesOfInterest
  let EnableDescriptionFilter = false;  // Filter 2: use DescriptionsOfInterest
  let EnableActionFilter      = false;  // Filter 3: use MatchActions
  let CategoriesOfInterest    = dynamic([
      "Targeted Malicious Activity was Detected",
      "Exploit Kit Activity Detected",
      "Domain Observed Used for C2 Detected",
      "Successful Credential Theft Detected",
      "Malware Command and Control Activity Detected",
      "Executable code was detected",
      "A Network Trojan was detected"
  ]);
  let DescriptionsOfInterest  = dynamic([
      "targeted-activity",
      "exploit-kit",
      "domain-c2",
      "credential-theft",
      "command-and-control",
      "shellcode-detect",
      "trojan-activity"
  ]);
  let MatchActions = dynamic(["Deny", "alert"]);
  AZFWIdpsSignature
  | where TimeGenerated >= ago(TimeWindow)
  | where Severity >= MinSeverity
  // Filter 1: Category filter (optional)
  | where (EnableCategoryFilter == false) or (Category has_any (CategoriesOfInterest))
  // Filter 2: Description filter (optional)
  | where (EnableDescriptionFilter == false) or (Description has_any (DescriptionsOfInterest))
  // Filter 3: Action filter (optional)
  | where (EnableActionFilter == false) or (Action in~ (MatchActions))
  | summarize
      StartTime   = min(TimeGenerated),
      EndTime     = max(TimeGenerated),
      TotalHits   = count(),
      MaxSeverity = max(Severity),
      Actions     = make_set(Action, 5),
      Signatures  = make_set(SignatureId, 20),
      Description = make_set(substring(tostring(Description), 0, 120), 3)
      by SourceIp, ThreatCategory = Category
  | where TotalHits >= HitThreshold
  | project
      StartTime,
      EndTime,
      SourceIp,
      ThreatCategory,
      TotalHits,
      MaxSeverity,
      Actions,
      Signatures,
      Description
  | order by MaxSeverity desc, TotalHits desc  
tactics:
- InitialAccess
- Exfiltration
- CredentialAccess
- CommandAndControl
- Execution
kind: Scheduled
description: |
    Identifies high severity malicious activity in Azure Firewall IDPS logs.
triggerOperator: gt

ARM