Multiple RDP connections from Single System

let endtime = 1d;
let starttime = 8d;
let threshold = 2.0;
(union isfuzzy=true
(SecurityEvent
| where TimeGenerated >= ago(endtime)
| where EventID == 4624 and LogonType == 10
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), ComputerCountToday = dcount(Computer), ComputerSet = makeset(Computer), ProcessSet = makeset(ProcessName)
by Account = tolower(Account), IpAddress, AccountType, Activity, LogonTypeName),
(WindowsEvent
| where TimeGenerated >= ago(endtime)
| where EventID == 4624
| extend LogonType = tostring(EventData.LogonType)
| where  LogonType == 10
| extend ProcessName = tostring(EventData.ProcessName)
| extend Account = strcat(tostring(EventData.TargetDomainName),"\\", tostring(EventData.TargetUserName))
| extend IpAddress = tostring(EventData.IpAddress)
| extend TargetUserSid = tostring(EventData.TargetUserSid)
| extend AccountType=case(Account endswith "$" or TargetUserSid in ("S-1-5-18", "S-1-5-19", "S-1-5-20"), "Machine", isempty(TargetUserSid), "", "User")
| extend Activity="4624 - An account was successfully logged on."
| extend LogonTypeName="10 - RemoteInteractive"
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), ComputerCountToday = dcount(Computer), ComputerSet = makeset(Computer), ProcessSet = makeset(ProcessName)
by Account = tolower(Account), IpAddress, AccountType, Activity, LogonTypeName)
)
| join kind=inner (
(union isfuzzy=true
(SecurityEvent
| where TimeGenerated >= ago(starttime) and TimeGenerated < ago(endtime)
| where EventID == 4624 and LogonType == 10
| summarize ComputerCountPrev7Days = dcount(Computer) by Account = tolower(Account), IpAddress
),
( WindowsEvent
| where TimeGenerated >= ago(starttime) and TimeGenerated < ago(endtime)
| where EventID == 4624  and EventData has ("10")
| extend LogonType = toint(EventData.LogonType)
| where  LogonType == 10
| extend Account = strcat(tostring(EventData.TargetDomainName),"\\", tostring(EventData.TargetUserName))
| extend IpAddress = tostring(EventData.IpAddress)
| summarize ComputerCountPrev7Days = dcount(Computer) by Account = tolower(Account), IpAddress)
)
) on Account, IpAddress
| extend Ratio = iff(isempty(ComputerCountPrev7Days), toreal(ComputerCountToday), ComputerCountToday / (ComputerCountPrev7Days * 1.0))
// Where the ratio of today to previous 7 days is more than double.
| where Ratio > threshold
| project StartTime, EndTime, Account, IpAddress, ComputerSet, ComputerCountToday, ComputerCountPrev7Days, Ratio, AccountType, Activity, LogonTypeName, ProcessSet
| extend AccountName = tostring(split(Account, @"\")[1]), AccountNTDomain = tostring(split(Account, @"\")[0])

id: 78422ef2-62bf-48ca-9bab-72c69818a425
requiredDataConnectors:
- connectorId: SecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: WindowsSecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: WindowsForwardedEvents
  dataTypes:
  - WindowsEvent
metadata:
  source:
    kind: Community
  author:
    name: Microsoft Security Research
  categories:
    domains:
    - Security - Threat Protection
  support:
    tier: Community
description: |
  'Identifies when an RDP connection is made to multiple systems and above the normal connection count for the previous 7 days.
  Connections from the same system with the same account within the same day.
  RDP connections are indicated by the EventID 4624 with LogonType = 10'  
severity: Low
tactics:
- LateralMovement
version: 1.2.6
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: Account
  - identifier: Name
    columnName: AccountName
  - identifier: NTDomain
    columnName: AccountNTDomain
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: IpAddress
  entityType: IP
triggerOperator: gt
triggerThreshold: 0
kind: Scheduled
queryFrequency: 1d
relevantTechniques:
- T1021
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/RDP_MultipleConnectionsFromSingleSystem.yaml
query: |
  let endtime = 1d;
  let starttime = 8d;
  let threshold = 2.0;
  (union isfuzzy=true
  (SecurityEvent
  | where TimeGenerated >= ago(endtime)
  | where EventID == 4624 and LogonType == 10
  | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), ComputerCountToday = dcount(Computer), ComputerSet = makeset(Computer), ProcessSet = makeset(ProcessName)
  by Account = tolower(Account), IpAddress, AccountType, Activity, LogonTypeName),
  (WindowsEvent
  | where TimeGenerated >= ago(endtime)
  | where EventID == 4624
  | extend LogonType = tostring(EventData.LogonType)
  | where  LogonType == 10
  | extend ProcessName = tostring(EventData.ProcessName)
  | extend Account = strcat(tostring(EventData.TargetDomainName),"\\", tostring(EventData.TargetUserName))
  | extend IpAddress = tostring(EventData.IpAddress)
  | extend TargetUserSid = tostring(EventData.TargetUserSid)
  | extend AccountType=case(Account endswith "$" or TargetUserSid in ("S-1-5-18", "S-1-5-19", "S-1-5-20"), "Machine", isempty(TargetUserSid), "", "User")
  | extend Activity="4624 - An account was successfully logged on."
  | extend LogonTypeName="10 - RemoteInteractive"
  | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), ComputerCountToday = dcount(Computer), ComputerSet = makeset(Computer), ProcessSet = makeset(ProcessName)
  by Account = tolower(Account), IpAddress, AccountType, Activity, LogonTypeName)
  )
  | join kind=inner (
  (union isfuzzy=true
  (SecurityEvent
  | where TimeGenerated >= ago(starttime) and TimeGenerated < ago(endtime)
  | where EventID == 4624 and LogonType == 10
  | summarize ComputerCountPrev7Days = dcount(Computer) by Account = tolower(Account), IpAddress
  ),
  ( WindowsEvent
  | where TimeGenerated >= ago(starttime) and TimeGenerated < ago(endtime)
  | where EventID == 4624  and EventData has ("10")
  | extend LogonType = toint(EventData.LogonType)
  | where  LogonType == 10
  | extend Account = strcat(tostring(EventData.TargetDomainName),"\\", tostring(EventData.TargetUserName))
  | extend IpAddress = tostring(EventData.IpAddress)
  | summarize ComputerCountPrev7Days = dcount(Computer) by Account = tolower(Account), IpAddress)
  )
  ) on Account, IpAddress
  | extend Ratio = iff(isempty(ComputerCountPrev7Days), toreal(ComputerCountToday), ComputerCountToday / (ComputerCountPrev7Days * 1.0))
  // Where the ratio of today to previous 7 days is more than double.
  | where Ratio > threshold
  | project StartTime, EndTime, Account, IpAddress, ComputerSet, ComputerCountToday, ComputerCountPrev7Days, Ratio, AccountType, Activity, LogonTypeName, ProcessSet
  | extend AccountName = tostring(split(Account, @"\")[1]), AccountNTDomain = tostring(split(Account, @"\")[0])  
name: Multiple RDP connections from Single System
queryPeriod: 8d

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/78422ef2-62bf-48ca-9bab-72c69818a425')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/78422ef2-62bf-48ca-9bab-72c69818a425')]",
      "properties": {
        "alertRuleTemplateName": "78422ef2-62bf-48ca-9bab-72c69818a425",
        "customDetails": null,
        "description": "'Identifies when an RDP connection is made to multiple systems and above the normal connection count for the previous 7 days.\nConnections from the same system with the same account within the same day.\nRDP connections are indicated by the EventID 4624 with LogonType = 10'\n",
        "displayName": "Multiple RDP connections from Single System",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "Account",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountNTDomain",
                "identifier": "NTDomain"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IpAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/RDP_MultipleConnectionsFromSingleSystem.yaml",
        "query": "let endtime = 1d;\nlet starttime = 8d;\nlet threshold = 2.0;\n(union isfuzzy=true\n(SecurityEvent\n| where TimeGenerated >= ago(endtime)\n| where EventID == 4624 and LogonType == 10\n| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), ComputerCountToday = dcount(Computer), ComputerSet = makeset(Computer), ProcessSet = makeset(ProcessName)\nby Account = tolower(Account), IpAddress, AccountType, Activity, LogonTypeName),\n(WindowsEvent\n| where TimeGenerated >= ago(endtime)\n| where EventID == 4624\n| extend LogonType = tostring(EventData.LogonType)\n| where  LogonType == 10\n| extend ProcessName = tostring(EventData.ProcessName)\n| extend Account = strcat(tostring(EventData.TargetDomainName),\"\\\\\", tostring(EventData.TargetUserName))\n| extend IpAddress = tostring(EventData.IpAddress)\n| extend TargetUserSid = tostring(EventData.TargetUserSid)\n| extend AccountType=case(Account endswith \"$\" or TargetUserSid in (\"S-1-5-18\", \"S-1-5-19\", \"S-1-5-20\"), \"Machine\", isempty(TargetUserSid), \"\", \"User\")\n| extend Activity=\"4624 - An account was successfully logged on.\"\n| extend LogonTypeName=\"10 - RemoteInteractive\"\n| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), ComputerCountToday = dcount(Computer), ComputerSet = makeset(Computer), ProcessSet = makeset(ProcessName)\nby Account = tolower(Account), IpAddress, AccountType, Activity, LogonTypeName)\n)\n| join kind=inner (\n(union isfuzzy=true\n(SecurityEvent\n| where TimeGenerated >= ago(starttime) and TimeGenerated < ago(endtime)\n| where EventID == 4624 and LogonType == 10\n| summarize ComputerCountPrev7Days = dcount(Computer) by Account = tolower(Account), IpAddress\n),\n( WindowsEvent\n| where TimeGenerated >= ago(starttime) and TimeGenerated < ago(endtime)\n| where EventID == 4624  and EventData has (\"10\")\n| extend LogonType = toint(EventData.LogonType)\n| where  LogonType == 10\n| extend Account = strcat(tostring(EventData.TargetDomainName),\"\\\\\", tostring(EventData.TargetUserName))\n| extend IpAddress = tostring(EventData.IpAddress)\n| summarize ComputerCountPrev7Days = dcount(Computer) by Account = tolower(Account), IpAddress)\n)\n) on Account, IpAddress\n| extend Ratio = iff(isempty(ComputerCountPrev7Days), toreal(ComputerCountToday), ComputerCountToday / (ComputerCountPrev7Days * 1.0))\n// Where the ratio of today to previous 7 days is more than double.\n| where Ratio > threshold\n| project StartTime, EndTime, Account, IpAddress, ComputerSet, ComputerCountToday, ComputerCountPrev7Days, Ratio, AccountType, Activity, LogonTypeName, ProcessSet\n| extend AccountName = tostring(split(Account, @\"\\\")[1]), AccountNTDomain = tostring(split(Account, @\"\\\")[0])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P8D",
        "severity": "Low",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "LateralMovement"
        ],
        "techniques": [
          "T1021"
        ],
        "templateVersion": "1.2.6",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}