Ngrok Reverse Proxy on Network ASIM DNS Solution
Id | 50b0dfb7-2c94-4eaf-a332-a5936d78c263 |
Rulename | Ngrok Reverse Proxy on Network (ASIM DNS Solution) |
Description | This detection identifies the top four Ngrok domains from DNS resolution. Ngrok reverse proxy can bypass network defense. While not inherently harmful, it has been used for malicious activities recently. |
Severity | Medium |
Tactics | CommandAndControl |
Techniques | T1572 T1090 T1102 |
Kind | Scheduled |
Query frequency | 1h |
Query period | 1h |
Trigger threshold | 0 |
Trigger operator | gt |
Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/NgrokReverseProxyOnNetwork.yaml |
Version | 1.0.0 |
Arm template | 50b0dfb7-2c94-4eaf-a332-a5936d78c263.json |
// Define a list of Ngrok domains
let NgrokDomains = dynamic(["ngrok.com", "ngrok.io", "ngrok", "tunnel.com", "korgn", "lennut.com"]);
// Query the _Im_Dns function for the past 1 hour
_Im_Dns(starttime=ago(1h))
| where isnotempty(DnsQuery) // Filter out empty DNS queries
| where DnsQuery has_any (NgrokDomains) // Filter DNS queries that match any of the Ngrok domains
| summarize Starttime = min(EventStartTime),Endtime=max(EventEndTime),EventsCount=sum(EventCount),EventResults=make_set(EventResult,4) by DnsQuery, Domain, SrcIpAddr, Dvc
// Summarize the data by Domain, DNS query, source IP address, and device Dvc
relevantTechniques:
- T1572
- T1090
- T1102
queryPeriod: 1h
tactics:
- CommandAndControl
requiredDataConnectors: []
eventGroupingSettings:
aggregationKind: AlertPerResult
triggerThreshold: 0
entityMappings:
- fieldMappings:
- identifier: Address
columnName: SrcIpAddr
entityType: IP
- fieldMappings:
- identifier: DomainName
columnName: Domain
entityType: DNS
name: Ngrok Reverse Proxy on Network (ASIM DNS Solution)
status: Available
tags:
- Schema: ASimDns
SchemaVersion: 0.1.6
query: |
// Define a list of Ngrok domains
let NgrokDomains = dynamic(["ngrok.com", "ngrok.io", "ngrok", "tunnel.com", "korgn", "lennut.com"]);
// Query the _Im_Dns function for the past 1 hour
_Im_Dns(starttime=ago(1h))
| where isnotempty(DnsQuery) // Filter out empty DNS queries
| where DnsQuery has_any (NgrokDomains) // Filter DNS queries that match any of the Ngrok domains
| summarize Starttime = min(EventStartTime),Endtime=max(EventEndTime),EventsCount=sum(EventCount),EventResults=make_set(EventResult,4) by DnsQuery, Domain, SrcIpAddr, Dvc
// Summarize the data by Domain, DNS query, source IP address, and device Dvc
queryFrequency: 1h
id: 50b0dfb7-2c94-4eaf-a332-a5936d78c263
severity: Medium
description: |
'This detection identifies the top four Ngrok domains from DNS resolution. Ngrok reverse proxy can bypass network defense. While not inherently harmful, it has been used for malicious activities recently.'
version: 1.0.0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/NgrokReverseProxyOnNetwork.yaml
kind: Scheduled
triggerOperator: gt
{
"$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/50b0dfb7-2c94-4eaf-a332-a5936d78c263')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/50b0dfb7-2c94-4eaf-a332-a5936d78c263')]",
"properties": {
"alertRuleTemplateName": "50b0dfb7-2c94-4eaf-a332-a5936d78c263",
"customDetails": null,
"description": "'This detection identifies the top four Ngrok domains from DNS resolution. Ngrok reverse proxy can bypass network defense. While not inherently harmful, it has been used for malicious activities recently.'\n",
"displayName": "Ngrok Reverse Proxy on Network (ASIM DNS Solution)",
"enabled": true,
"entityMappings": [
{
"entityType": "IP",
"fieldMappings": [
{
"columnName": "SrcIpAddr",
"identifier": "Address"
}
]
},
{
"entityType": "DNS",
"fieldMappings": [
{
"columnName": "Domain",
"identifier": "DomainName"
}
]
}
],
"eventGroupingSettings": {
"aggregationKind": "AlertPerResult"
},
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/NgrokReverseProxyOnNetwork.yaml",
"query": "// Define a list of Ngrok domains\nlet NgrokDomains = dynamic([\"ngrok.com\", \"ngrok.io\", \"ngrok\", \"tunnel.com\", \"korgn\", \"lennut.com\"]);\n// Query the _Im_Dns function for the past 1 hour\n_Im_Dns(starttime=ago(1h))\n| where isnotempty(DnsQuery) // Filter out empty DNS queries\n| where DnsQuery has_any (NgrokDomains) // Filter DNS queries that match any of the Ngrok domains\n| summarize Starttime = min(EventStartTime),Endtime=max(EventEndTime),EventsCount=sum(EventCount),EventResults=make_set(EventResult,4) by DnsQuery, Domain, SrcIpAddr, Dvc\n// Summarize the data by Domain, DNS query, source IP address, and device Dvc\n",
"queryFrequency": "PT1H",
"queryPeriod": "PT1H",
"severity": "Medium",
"status": "Available",
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"CommandAndControl"
],
"tags": [
{
"Schema": "ASimDns",
"SchemaVersion": "0.1.6"
}
],
"techniques": [
"T1090",
"T1102",
"T1572"
],
"templateVersion": "1.0.0",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}