Cisco - firewall block but success logon to Microsoft Entra ID

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Id	157c0cfc-d76d-463b-8755-c781608cdc1a
Rulename	Cisco - firewall block but success logon to Microsoft Entra ID
Description	Correlate IPs blocked by a Cisco firewall appliance with successful Microsoft Entra ID signins. Because the IP was blocked by the firewall, that same IP logging on successfully to Entra ID is potentially suspect and could indicate credential compromise for the user account.
Severity	Medium
Tactics	InitialAccess
Techniques	T1078
Required data connectors	AzureActiveDirectory CiscoASA
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/SigninFirewallCorrelation.yaml
Version	1.0.6
Arm template	157c0cfc-d76d-463b-8755-c781608cdc1a.json

KQL

let aadFunc = (tableName:string){
CommonSecurityLog
| where DeviceVendor =~ "Cisco"
| where DeviceAction =~ "denied"
| where ipv4_is_private(SourceIP) == false
| summarize count() by SourceIP
| join (
    // Successful signins from IPs blocked by the firewall solution are suspect
    // Include fully successful sign-ins, but also ones that failed only at MFA stage
    // as that supposes the password was sucessfully guessed.
  table(tableName)
  | where ResultType in ("0", "50074", "50076")
) on $left.SourceIP == $right.IPAddress
| extend AccountName = tostring(split(Account, "@")[0]), AccountUPNSuffix = tostring(split(Account, "@")[1])
};
let aadSignin = aadFunc("SigninLogs");
let aadNonInt = aadFunc("AADNonInteractiveUserSignInLogs");
union isfuzzy=true aadSignin, aadNonInt

YAML

name: Cisco - firewall block but success logon to Microsoft Entra ID
query: |
  let aadFunc = (tableName:string){
  CommonSecurityLog
  | where DeviceVendor =~ "Cisco"
  | where DeviceAction =~ "denied"
  | where ipv4_is_private(SourceIP) == false
  | summarize count() by SourceIP
  | join (
      // Successful signins from IPs blocked by the firewall solution are suspect
      // Include fully successful sign-ins, but also ones that failed only at MFA stage
      // as that supposes the password was sucessfully guessed.
    table(tableName)
    | where ResultType in ("0", "50074", "50076")
  ) on $left.SourceIP == $right.IPAddress
  | extend AccountName = tostring(split(Account, "@")[0]), AccountUPNSuffix = tostring(split(Account, "@")[1])
  };
  let aadSignin = aadFunc("SigninLogs");
  let aadNonInt = aadFunc("AADNonInteractiveUserSignInLogs");
  union isfuzzy=true aadSignin, aadNonInt  
queryFrequency: 1d
triggerOperator: gt
requiredDataConnectors:
- dataTypes:
  - CommonSecurityLog
  connectorId: CiscoASA
- dataTypes:
  - SigninLogs
  connectorId: AzureActiveDirectory
- dataTypes:
  - AADNonInteractiveUserSignInLogs
  connectorId: AzureActiveDirectory
entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: FullName
    columnName: UserPrincipalName
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: SourceIP
triggerThreshold: 0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/SigninFirewallCorrelation.yaml
description: |
  'Correlate IPs blocked by a Cisco firewall appliance with successful Microsoft Entra ID signins.
  Because the IP was blocked by the firewall, that same IP logging on successfully to Entra ID is potentially suspect and could indicate credential compromise for the user account.'  
version: 1.0.6
id: 157c0cfc-d76d-463b-8755-c781608cdc1a
kind: Scheduled
relevantTechniques:
- T1078
metadata:
  support:
    tier: Community
  categories:
    domains:
    - Security - Network
  author:
    name: Microsoft Security Resarch
  source:
    kind: Community
severity: Medium
tactics:
- InitialAccess
queryPeriod: 1d

ARM