RDP Nesting

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Id	69a45b05-71f5-45ca-8944-2e038747fb39
Rulename	RDP Nesting
Description	Query detects potential lateral movement within a network by identifying when an RDP connection (EventID 4624, LogonType 10) is made to an initial system, followed by a subsequent RDP connection from that system to another, using the same account within a 60-minute window. To reduce false positives, it excludes scenarios where the same account has made 5 or more connections to the same set of computers in the previous 7 days. This approach focuses on highlighting unusual RDP behaviour that suggests lateral movement, which is often associated with attacker tactics during a network breach.
Severity	Medium
Tactics	LateralMovement
Techniques	T1021
Required data connectors	SecurityEvents WindowsForwardedEvents WindowsSecurityEvents
Kind	Scheduled
Query frequency	1d
Query period	8d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/RDP_Nesting.yaml
Version	1.2.8
Arm template	69a45b05-71f5-45ca-8944-2e038747fb39.json

KQL

let endtime = 1d;
// Function to resolve hostname to IP address using DNS logs or a lookup table (example syntax)
let rdpConnections =
(union isfuzzy=true
(
SecurityEvent
| where TimeGenerated >= ago(endtime)
| where EventID == 4624 and LogonType == 10
// Labeling the first RDP connection time, computer and ip
| extend
FirstHop = bin(TimeGenerated, 1m),
FirstComputer = toupper(Computer),
FirstRemoteIPAddress = IpAddress,
Account = tolower(Account)
),
(
WindowsEvent
| where TimeGenerated >= ago(endtime)
| where EventID == 4624 and EventData has ("10")
| extend LogonType = tostring(EventData.LogonType)
| where LogonType == 10 // Labeling the first RDP connection time, computer and ip
| extend Account = strcat(tostring(EventData.TargetDomainName), "", tostring(EventData.TargetUserName))
| extend IpAddress = tostring(EventData.IpAddress)
| extend
FirstHop = bin(TimeGenerated, 1m),
FirstComputer = toupper(Computer),
FirstRemoteIPAddress = IpAddress,
Account = tolower(Account)
))
| join kind=inner (
(union isfuzzy=true
(
SecurityEvent
| where TimeGenerated >= ago(endtime)
| where EventID == 4624 and LogonType == 10
// Labeling the second RDP connection time, computer and ip
| extend
SecondHop = bin(TimeGenerated, 1m),
SecondComputer = toupper(Computer),
SecondRemoteIPAddress = IpAddress,
Account = tolower(Account)
),
(
WindowsEvent
| where TimeGenerated >= ago(endtime)
| where EventID == 4624 and EventData has ("10")
| extend LogonType = toint(EventData.LogonType)
| where LogonType == 10 // Labeling the second RDP connection time, computer and ip
| extend Account = strcat(tostring(EventData.TargetDomainName), "", tostring(EventData.TargetUserName))
| extend IpAddress = tostring(EventData.IpAddress)
| extend
SecondHop = bin(TimeGenerated, 1m),
SecondComputer = toupper(Computer),
SecondRemoteIPAddress = IpAddress,
Account = tolower(Account)
))
)
on Account
| distinct
Account,
FirstHop,
FirstComputer,
FirstRemoteIPAddress,
SecondHop,
SecondComputer,
SecondRemoteIPAddress,
AccountType,
Activity,
LogonTypeName,
ProcessName;
// Resolve hostnames to IP addresses device network Ip's
let listOfFirstComputer = rdpConnections | distinct FirstComputer;
let listOfSecondComputer = rdpConnections | distinct SecondComputer;
let resolvedIPs =
DeviceNetworkInfo
| where TimeGenerated >= ago(endtime)
| where isnotempty(ConnectedNetworks) and NetworkAdapterStatus == "Up"
| extend ClientIP = tostring(parse_json(IPAddresses[0]).IPAddress)
| where isnotempty(ClientIP)
| where DeviceName in~ (listOfFirstComputer) or DeviceName in~ (listOfSecondComputer)
| summarize arg_max(TimeGenerated, ClientIP) by Computer= DeviceName
| project Computer=toupper(Computer), ResolvedIP = ClientIP;
// Join resolved IPs with the RDP connections
rdpConnections
| join kind=inner (resolvedIPs) on $left.FirstComputer == $right.Computer
| join kind=inner (resolvedIPs) on $left.SecondComputer == $right.Computer
// | where ResolvedIP != ResolvedIP1
| distinct
Account,
FirstHop,
FirstComputer,
FirstComputerIP = ResolvedIP,
FirstRemoteIPAddress,
SecondHop,
SecondComputer,
SecondComputerIP = ResolvedIP1,
SecondRemoteIPAddress,
AccountType,
Activity,
LogonTypeName,
ProcessName
// Ensure the first connection is before the second connection
// Identify only RDP to another computer from within the first RDP connection by only choosing matches where the Computer names do not match
// Ensure the IPAddresses do not match by excluding connections from the same computers with first hop RDP connections to multiple computers
| where FirstComputer != SecondComputer
and FirstRemoteIPAddress != SecondRemoteIPAddress
and SecondHop > FirstHop
// Ensure the second hop occurs within 30 minutes of the first hop
| where SecondHop <= FirstHop + 30m
| where SecondRemoteIPAddress == FirstComputerIP
| summarize FirstHopFirstSeen = min(FirstHop), FirstHopLastSeen = max(FirstHop)
by
Account,
FirstComputer,
FirstComputerIP,
FirstRemoteIPAddress,
SecondHop,
SecondComputer,
SecondComputerIP,
SecondRemoteIPAddress,
AccountType,
Activity,
LogonTypeName,
ProcessName
| extend
AccountName = tostring(split(Account, @"")[1]),
AccountNTDomain = tostring(split(Account, @"")[0])
| extend
HostName1 = tostring(split(FirstComputer, ".")[0]),
DomainIndex = toint(indexof(FirstComputer, '.'))
| extend HostNameDomain1 = iff(DomainIndex != -1, substring(FirstComputer, DomainIndex + 1), FirstComputer)
| extend
HostName2 = tostring(split(SecondComputer, ".")[0]),
DomainIndex = toint(indexof(SecondComputer, '.'))
| extend HostNameDomain2 = iff(DomainIndex != -1, substring(SecondComputer, DomainIndex + 1), SecondComputer)
| project-away DomainIndex

YAML

relevantTechniques:
- T1021
name: RDP Nesting
requiredDataConnectors:
- dataTypes:
  - SecurityEvent
  connectorId: SecurityEvents
- dataTypes:
  - SecurityEvent
  connectorId: WindowsSecurityEvents
- dataTypes:
  - WindowsEvent
  connectorId: WindowsForwardedEvents
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: Account
  - identifier: Name
    columnName: AccountName
  - identifier: NTDomain
    columnName: AccountNTDomain
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: FirstComputer
  - identifier: HostName
    columnName: HostName1
  - identifier: NTDomain
    columnName: HostNameDomain1
  entityType: Host
- fieldMappings:
  - identifier: FullName
    columnName: SecondComputer
  - identifier: HostName
    columnName: HostName2
  - identifier: NTDomain
    columnName: HostNameDomain2
  entityType: Host
- fieldMappings:
  - identifier: Address
    columnName: FirstIPAddress
  entityType: IP
triggerThreshold: 0
id: 69a45b05-71f5-45ca-8944-2e038747fb39
tactics:
- LateralMovement
version: 1.2.8
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/RDP_Nesting.yaml
queryPeriod: 8d
kind: Scheduled
metadata:
  categories:
    domains:
    - Security - Threat Protection
  author:
    name: Microsoft Security Research
  support:
    tier: Community
  source:
    kind: Community
queryFrequency: 1d
severity: Medium
description: |
  'Query detects potential lateral movement within a network by identifying when an RDP connection (EventID 4624, LogonType 10) is made to an initial system, followed by a subsequent RDP connection from that system to another, using the same account within a 60-minute window.
   To reduce false positives, it excludes scenarios where the same account has made 5 or more connections to the same set of computers in the previous 7 days. This approach focuses on highlighting unusual RDP behaviour that suggests lateral movement, which is often associated with attacker tactics during a network breach.'  
query: |
  let endtime = 1d;
  // Function to resolve hostname to IP address using DNS logs or a lookup table (example syntax)
  let rdpConnections =
  (union isfuzzy=true
  (
  SecurityEvent
  | where TimeGenerated >= ago(endtime)
  | where EventID == 4624 and LogonType == 10
  // Labeling the first RDP connection time, computer and ip
  | extend
  FirstHop = bin(TimeGenerated, 1m),
  FirstComputer = toupper(Computer),
  FirstRemoteIPAddress = IpAddress,
  Account = tolower(Account)
  ),
  (
  WindowsEvent
  | where TimeGenerated >= ago(endtime)
  | where EventID == 4624 and EventData has ("10")
  | extend LogonType = tostring(EventData.LogonType)
  | where LogonType == 10 // Labeling the first RDP connection time, computer and ip
  | extend Account = strcat(tostring(EventData.TargetDomainName), "", tostring(EventData.TargetUserName))
  | extend IpAddress = tostring(EventData.IpAddress)
  | extend
  FirstHop = bin(TimeGenerated, 1m),
  FirstComputer = toupper(Computer),
  FirstRemoteIPAddress = IpAddress,
  Account = tolower(Account)
  ))
  | join kind=inner (
  (union isfuzzy=true
  (
  SecurityEvent
  | where TimeGenerated >= ago(endtime)
  | where EventID == 4624 and LogonType == 10
  // Labeling the second RDP connection time, computer and ip
  | extend
  SecondHop = bin(TimeGenerated, 1m),
  SecondComputer = toupper(Computer),
  SecondRemoteIPAddress = IpAddress,
  Account = tolower(Account)
  ),
  (
  WindowsEvent
  | where TimeGenerated >= ago(endtime)
  | where EventID == 4624 and EventData has ("10")
  | extend LogonType = toint(EventData.LogonType)
  | where LogonType == 10 // Labeling the second RDP connection time, computer and ip
  | extend Account = strcat(tostring(EventData.TargetDomainName), "", tostring(EventData.TargetUserName))
  | extend IpAddress = tostring(EventData.IpAddress)
  | extend
  SecondHop = bin(TimeGenerated, 1m),
  SecondComputer = toupper(Computer),
  SecondRemoteIPAddress = IpAddress,
  Account = tolower(Account)
  ))
  )
  on Account
  | distinct
  Account,
  FirstHop,
  FirstComputer,
  FirstRemoteIPAddress,
  SecondHop,
  SecondComputer,
  SecondRemoteIPAddress,
  AccountType,
  Activity,
  LogonTypeName,
  ProcessName;
  // Resolve hostnames to IP addresses device network Ip's
  let listOfFirstComputer = rdpConnections | distinct FirstComputer;
  let listOfSecondComputer = rdpConnections | distinct SecondComputer;
  let resolvedIPs =
  DeviceNetworkInfo
  | where TimeGenerated >= ago(endtime)
  | where isnotempty(ConnectedNetworks) and NetworkAdapterStatus == "Up"
  | extend ClientIP = tostring(parse_json(IPAddresses[0]).IPAddress)
  | where isnotempty(ClientIP)
  | where DeviceName in~ (listOfFirstComputer) or DeviceName in~ (listOfSecondComputer)
  | summarize arg_max(TimeGenerated, ClientIP) by Computer= DeviceName
  | project Computer=toupper(Computer), ResolvedIP = ClientIP;
  // Join resolved IPs with the RDP connections
  rdpConnections
  | join kind=inner (resolvedIPs) on $left.FirstComputer == $right.Computer
  | join kind=inner (resolvedIPs) on $left.SecondComputer == $right.Computer
  // | where ResolvedIP != ResolvedIP1
  | distinct
  Account,
  FirstHop,
  FirstComputer,
  FirstComputerIP = ResolvedIP,
  FirstRemoteIPAddress,
  SecondHop,
  SecondComputer,
  SecondComputerIP = ResolvedIP1,
  SecondRemoteIPAddress,
  AccountType,
  Activity,
  LogonTypeName,
  ProcessName
  // Ensure the first connection is before the second connection
  // Identify only RDP to another computer from within the first RDP connection by only choosing matches where the Computer names do not match
  // Ensure the IPAddresses do not match by excluding connections from the same computers with first hop RDP connections to multiple computers
  | where FirstComputer != SecondComputer
  and FirstRemoteIPAddress != SecondRemoteIPAddress
  and SecondHop > FirstHop
  // Ensure the second hop occurs within 30 minutes of the first hop
  | where SecondHop <= FirstHop + 30m
  | where SecondRemoteIPAddress == FirstComputerIP
  | summarize FirstHopFirstSeen = min(FirstHop), FirstHopLastSeen = max(FirstHop)
  by
  Account,
  FirstComputer,
  FirstComputerIP,
  FirstRemoteIPAddress,
  SecondHop,
  SecondComputer,
  SecondComputerIP,
  SecondRemoteIPAddress,
  AccountType,
  Activity,
  LogonTypeName,
  ProcessName
  | extend
  AccountName = tostring(split(Account, @"")[1]),
  AccountNTDomain = tostring(split(Account, @"")[0])
  | extend
  HostName1 = tostring(split(FirstComputer, ".")[0]),
  DomainIndex = toint(indexof(FirstComputer, '.'))
  | extend HostNameDomain1 = iff(DomainIndex != -1, substring(FirstComputer, DomainIndex + 1), FirstComputer)
  | extend
  HostName2 = tostring(split(SecondComputer, ".")[0]),
  DomainIndex = toint(indexof(SecondComputer, '.'))
  | extend HostNameDomain2 = iff(DomainIndex != -1, substring(SecondComputer, DomainIndex + 1), SecondComputer)
  | project-away DomainIndex  
triggerOperator: gt

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/69a45b05-71f5-45ca-8944-2e038747fb39')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/69a45b05-71f5-45ca-8944-2e038747fb39')]",
      "properties": {
        "alertRuleTemplateName": "69a45b05-71f5-45ca-8944-2e038747fb39",
        "customDetails": null,
        "description": "'Query detects potential lateral movement within a network by identifying when an RDP connection (EventID 4624, LogonType 10) is made to an initial system, followed by a subsequent RDP connection from that system to another, using the same account within a 60-minute window.\n To reduce false positives, it excludes scenarios where the same account has made 5 or more connections to the same set of computers in the previous 7 days. This approach focuses on highlighting unusual RDP behaviour that suggests lateral movement, which is often associated with attacker tactics during a network breach.'\n",
        "displayName": "RDP Nesting",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "Account",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountNTDomain",
                "identifier": "NTDomain"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "FirstComputer",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName1",
                "identifier": "HostName"
              },
              {
                "columnName": "HostNameDomain1",
                "identifier": "NTDomain"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "SecondComputer",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName2",
                "identifier": "HostName"
              },
              {
                "columnName": "HostNameDomain2",
                "identifier": "NTDomain"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "FirstIPAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/RDP_Nesting.yaml",
        "query": "let endtime = 1d;\n// Function to resolve hostname to IP address using DNS logs or a lookup table (example syntax)\nlet rdpConnections =\n(union isfuzzy=true\n(\nSecurityEvent\n| where TimeGenerated >= ago(endtime)\n| where EventID == 4624 and LogonType == 10\n// Labeling the first RDP connection time, computer and ip\n| extend\nFirstHop = bin(TimeGenerated, 1m),\nFirstComputer = toupper(Computer),\nFirstRemoteIPAddress = IpAddress,\nAccount = tolower(Account)\n),\n(\nWindowsEvent\n| where TimeGenerated >= ago(endtime)\n| where EventID == 4624 and EventData has (\"10\")\n| extend LogonType = tostring(EventData.LogonType)\n| where LogonType == 10 // Labeling the first RDP connection time, computer and ip\n| extend Account = strcat(tostring(EventData.TargetDomainName), \"\", tostring(EventData.TargetUserName))\n| extend IpAddress = tostring(EventData.IpAddress)\n| extend\nFirstHop = bin(TimeGenerated, 1m),\nFirstComputer = toupper(Computer),\nFirstRemoteIPAddress = IpAddress,\nAccount = tolower(Account)\n))\n| join kind=inner (\n(union isfuzzy=true\n(\nSecurityEvent\n| where TimeGenerated >= ago(endtime)\n| where EventID == 4624 and LogonType == 10\n// Labeling the second RDP connection time, computer and ip\n| extend\nSecondHop = bin(TimeGenerated, 1m),\nSecondComputer = toupper(Computer),\nSecondRemoteIPAddress = IpAddress,\nAccount = tolower(Account)\n),\n(\nWindowsEvent\n| where TimeGenerated >= ago(endtime)\n| where EventID == 4624 and EventData has (\"10\")\n| extend LogonType = toint(EventData.LogonType)\n| where LogonType == 10 // Labeling the second RDP connection time, computer and ip\n| extend Account = strcat(tostring(EventData.TargetDomainName), \"\", tostring(EventData.TargetUserName))\n| extend IpAddress = tostring(EventData.IpAddress)\n| extend\nSecondHop = bin(TimeGenerated, 1m),\nSecondComputer = toupper(Computer),\nSecondRemoteIPAddress = IpAddress,\nAccount = tolower(Account)\n))\n)\non Account\n| distinct\nAccount,\nFirstHop,\nFirstComputer,\nFirstRemoteIPAddress,\nSecondHop,\nSecondComputer,\nSecondRemoteIPAddress,\nAccountType,\nActivity,\nLogonTypeName,\nProcessName;\n// Resolve hostnames to IP addresses device network Ip's\nlet listOfFirstComputer = rdpConnections | distinct FirstComputer;\nlet listOfSecondComputer = rdpConnections | distinct SecondComputer;\nlet resolvedIPs =\nDeviceNetworkInfo\n| where TimeGenerated >= ago(endtime)\n| where isnotempty(ConnectedNetworks) and NetworkAdapterStatus == \"Up\"\n| extend ClientIP = tostring(parse_json(IPAddresses[0]).IPAddress)\n| where isnotempty(ClientIP)\n| where DeviceName in~ (listOfFirstComputer) or DeviceName in~ (listOfSecondComputer)\n| summarize arg_max(TimeGenerated, ClientIP) by Computer= DeviceName\n| project Computer=toupper(Computer), ResolvedIP = ClientIP;\n// Join resolved IPs with the RDP connections\nrdpConnections\n| join kind=inner (resolvedIPs) on $left.FirstComputer == $right.Computer\n| join kind=inner (resolvedIPs) on $left.SecondComputer == $right.Computer\n// | where ResolvedIP != ResolvedIP1\n| distinct\nAccount,\nFirstHop,\nFirstComputer,\nFirstComputerIP = ResolvedIP,\nFirstRemoteIPAddress,\nSecondHop,\nSecondComputer,\nSecondComputerIP = ResolvedIP1,\nSecondRemoteIPAddress,\nAccountType,\nActivity,\nLogonTypeName,\nProcessName\n// Ensure the first connection is before the second connection\n// Identify only RDP to another computer from within the first RDP connection by only choosing matches where the Computer names do not match\n// Ensure the IPAddresses do not match by excluding connections from the same computers with first hop RDP connections to multiple computers\n| where FirstComputer != SecondComputer\nand FirstRemoteIPAddress != SecondRemoteIPAddress\nand SecondHop > FirstHop\n// Ensure the second hop occurs within 30 minutes of the first hop\n| where SecondHop <= FirstHop + 30m\n| where SecondRemoteIPAddress == FirstComputerIP\n| summarize FirstHopFirstSeen = min(FirstHop), FirstHopLastSeen = max(FirstHop)\nby\nAccount,\nFirstComputer,\nFirstComputerIP,\nFirstRemoteIPAddress,\nSecondHop,\nSecondComputer,\nSecondComputerIP,\nSecondRemoteIPAddress,\nAccountType,\nActivity,\nLogonTypeName,\nProcessName\n| extend\nAccountName = tostring(split(Account, @\"\")[1]),\nAccountNTDomain = tostring(split(Account, @\"\")[0])\n| extend\nHostName1 = tostring(split(FirstComputer, \".\")[0]),\nDomainIndex = toint(indexof(FirstComputer, '.'))\n| extend HostNameDomain1 = iff(DomainIndex != -1, substring(FirstComputer, DomainIndex + 1), FirstComputer)\n| extend\nHostName2 = tostring(split(SecondComputer, \".\")[0]),\nDomainIndex = toint(indexof(SecondComputer, '.'))\n| extend HostNameDomain2 = iff(DomainIndex != -1, substring(SecondComputer, DomainIndex + 1), SecondComputer)\n| project-away DomainIndex\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P8D",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "LateralMovement"
        ],
        "techniques": [
          "T1021"
        ],
        "templateVersion": "1.2.8",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}