Potential DGA(Domain Generation Algorithm) detected via Repetitive Failures - Static threshold based (ASIM DNS Solution)
Id | 89ba52fa-96a7-4653-829a-ca49bb13336c |
Rulename | Potential DGA(Domain Generation Algorithm) detected via Repetitive Failures - Static threshold based (ASIM DNS Solution) |
Description | This rule identifies clients with a high NXDomain count, which could be indicative of a DGA (cycling through possible C2 domains where most C2s are not live). An alert is generated when a new IP address is seen (based on not being seen associated with NXDomain records in prior 10-day baseline period).\n\nIt utilizes ASIM normalization and is applied to any source that supports the ASIM DNS schema. |
Severity | Medium |
Tactics | CommandAndControl |
Techniques | T1568 T1008 |
Required data connectors | AIVectraStream ASimDnsActivityLogs AzureFirewall CiscoUmbrellaDataConnector Corelight DNS GCPDNSDataConnector InfobloxNIOS ISCBind NXLogDnsLogs WindowsForwardedEvents Zscaler |
Kind | Scheduled |
Query frequency | 1d |
Query period | 10d |
Trigger threshold | 0 |
Trigger operator | gt |
Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/PotentialDGADetectedviaRepetitiveFailuresStaticThresholdBased.yaml |
Version | 1.0.0 |
Arm template | 89ba52fa-96a7-4653-829a-ca49bb13336c.json |
let threshold = materialize (_GetWatchlist('DNS_Solution_Monitoring_Configuration')
| where wl_RuleName == 'Potential DGA(Domain Generation Algorithm) detected' and wl_Type == 'Detection'
| project toint(wl_Threshold));
let lookback = 10d;
let referenceendtime = 1d;
let nxDomainDnsEvents = (stime: datetime, etime: datetime) {
_Im_Dns(responsecodename='NXDOMAIN', starttime=stime, endtime=etime)
| where DnsQueryTypeName in ("A", "AAAA")
| where ipv4_is_match("127.0.0.1", SrcIpAddr) == False
| where DnsQuery !contains "/" and DnsQuery contains "."
};
nxDomainDnsEvents (stime=ago(referenceendtime), etime=now())
| summarize
StartTimeUtc = min(TimeGenerated),
EndTimeUtc = max(TimeGenerated),
DNSQueryCount=dcount(DnsQuery)
by SrcIpAddr
| where DNSQueryCount > toscalar(threshold)
// Filter out previously seen IPs
| join kind=leftanti (nxDomainDnsEvents (stime=ago(lookback), etime=ago(referenceendtime))
| summarize DNSQueryCount=dcount(DnsQuery) by SrcIpAddr
| where DNSQueryCount > toscalar(threshold))
on SrcIpAddr
// Pull out sample NXDomain responses for those remaining potentially infected IPs
| join kind = inner (nxDomainDnsEvents (stime=ago(lookback), etime=now())
| summarize by DnsQuery, SrcIpAddr)
on SrcIpAddr
| summarize
StartTimeUtc = min(StartTimeUtc),
EndTimeUtc = max(EndTimeUtc),
DNSQueries=make_list(DnsQuery, 100)
by SrcIpAddr, DNSQueryCount
| extend DNSQueryThreshold=toint(toscalar(threshold))
queryFrequency: 1d
alertDetailsOverride:
alertDisplayNameFormat: "[Static threshold] Potential DGA (Domain Generation Algorithm) originating from client IP: '{{SrcIpAddr}}' has been detected."
alertDescriptionFormat: |-
Client has been identified with high NXDomain count which could be indicative of a DGA (cycling through possible C2 domains where most C2s are not live). This client is found to be communicating with multiple Domains which do not exist.
DGA DNS query count baseline is: '{{DNSQueryThreshold}}'
Current failed DNS query count from this client: '{{DNSQueryCount}}'
DNS queries requested by this client inlcude: '{{DNSQueries}}'
triggerOperator: gt
tactics:
- CommandAndControl
description: |
'This rule identifies clients with a high NXDomain count, which could be indicative of a DGA (cycling through possible C2 domains where most C2s are not live). An alert is generated when a new IP address is seen (based on not being seen associated with NXDomain records in prior 10-day baseline period).\n\nIt utilizes [ASIM](https://aka.ms/AboutASIM) normalization and is applied to any source that supports the ASIM DNS schema.'
eventGroupingSettings:
aggregationKind: AlertPerResult
status: Available
relevantTechniques:
- T1568
- T1008
name: Potential DGA(Domain Generation Algorithm) detected via Repetitive Failures - Static threshold based (ASIM DNS Solution)
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/PotentialDGADetectedviaRepetitiveFailuresStaticThresholdBased.yaml
severity: Medium
triggerThreshold: 0
version: 1.0.0
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: SrcIpAddr
tags:
- Schema: ASimDns
SchemaVersion: 0.1.6
customDetails:
DNSQueryCount: DNSQueryCount
DNSQueries: DNSQueries
DNSQueryThreshold: DNSQueryThreshold
id: 89ba52fa-96a7-4653-829a-ca49bb13336c
requiredDataConnectors:
- connectorId: ASimDnsActivityLogs
dataTypes:
- ASimDnsActivityLogs
- connectorId: GCPDNSDataConnector
dataTypes:
- GCP_DNS_CL
- connectorId: AzureFirewall
dataTypes:
- AzureDiagnostics
- connectorId: CiscoUmbrellaDataConnector
dataTypes:
- Cisco_Umbrella_proxy_CL
- connectorId: Corelight
dataTypes:
- Corelight_CL
- connectorId: InfobloxNIOS
dataTypes:
- Syslog
- connectorId: NXLogDnsLogs
dataTypes:
- NXLog_DNS_Server_CL
- connectorId: DNS
dataTypes:
- DnsEvents
- connectorId: AIVectraStream
dataTypes:
- VectraStream_CL
- connectorId: WindowsForwardedEvents
dataTypes:
- WindowsEvents
- connectorId: Zscaler
dataTypes:
- CommonSecurityLog
- connectorId: ISCBind
dataTypes:
- Syslog
kind: Scheduled
query: |
let threshold = materialize (_GetWatchlist('DNS_Solution_Monitoring_Configuration')
| where wl_RuleName == 'Potential DGA(Domain Generation Algorithm) detected' and wl_Type == 'Detection'
| project toint(wl_Threshold));
let lookback = 10d;
let referenceendtime = 1d;
let nxDomainDnsEvents = (stime: datetime, etime: datetime) {
_Im_Dns(responsecodename='NXDOMAIN', starttime=stime, endtime=etime)
| where DnsQueryTypeName in ("A", "AAAA")
| where ipv4_is_match("127.0.0.1", SrcIpAddr) == False
| where DnsQuery !contains "/" and DnsQuery contains "."
};
nxDomainDnsEvents (stime=ago(referenceendtime), etime=now())
| summarize
StartTimeUtc = min(TimeGenerated),
EndTimeUtc = max(TimeGenerated),
DNSQueryCount=dcount(DnsQuery)
by SrcIpAddr
| where DNSQueryCount > toscalar(threshold)
// Filter out previously seen IPs
| join kind=leftanti (nxDomainDnsEvents (stime=ago(lookback), etime=ago(referenceendtime))
| summarize DNSQueryCount=dcount(DnsQuery) by SrcIpAddr
| where DNSQueryCount > toscalar(threshold))
on SrcIpAddr
// Pull out sample NXDomain responses for those remaining potentially infected IPs
| join kind = inner (nxDomainDnsEvents (stime=ago(lookback), etime=now())
| summarize by DnsQuery, SrcIpAddr)
on SrcIpAddr
| summarize
StartTimeUtc = min(StartTimeUtc),
EndTimeUtc = max(EndTimeUtc),
DNSQueries=make_list(DnsQuery, 100)
by SrcIpAddr, DNSQueryCount
| extend DNSQueryThreshold=toint(toscalar(threshold))
queryPeriod: 10d
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"workspace": {
"type": "String"
}
},
"resources": [
{
"id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/89ba52fa-96a7-4653-829a-ca49bb13336c')]",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/89ba52fa-96a7-4653-829a-ca49bb13336c')]",
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
"kind": "Scheduled",
"apiVersion": "2022-11-01",
"properties": {
"displayName": "Potential DGA(Domain Generation Algorithm) detected via Repetitive Failures - Static threshold based (ASIM DNS Solution)",
"description": "'This rule identifies clients with a high NXDomain count, which could be indicative of a DGA (cycling through possible C2 domains where most C2s are not live). An alert is generated when a new IP address is seen (based on not being seen associated with NXDomain records in prior 10-day baseline period).\\n\\nIt utilizes [ASIM](https://aka.ms/AboutASIM) normalization and is applied to any source that supports the ASIM DNS schema.'\n",
"severity": "Medium",
"enabled": true,
"query": "let threshold = materialize (_GetWatchlist('DNS_Solution_Monitoring_Configuration')\n | where wl_RuleName == 'Potential DGA(Domain Generation Algorithm) detected' and wl_Type == 'Detection'\n | project toint(wl_Threshold));\nlet lookback = 10d;\nlet referenceendtime = 1d;\nlet nxDomainDnsEvents = (stime: datetime, etime: datetime) {\n _Im_Dns(responsecodename='NXDOMAIN', starttime=stime, endtime=etime)\n | where DnsQueryTypeName in (\"A\", \"AAAA\")\n | where ipv4_is_match(\"127.0.0.1\", SrcIpAddr) == False\n | where DnsQuery !contains \"/\" and DnsQuery contains \".\"\n};\nnxDomainDnsEvents (stime=ago(referenceendtime), etime=now())\n| summarize\n StartTimeUtc = min(TimeGenerated),\n EndTimeUtc = max(TimeGenerated),\n DNSQueryCount=dcount(DnsQuery)\n by SrcIpAddr\n| where DNSQueryCount > toscalar(threshold)\n// Filter out previously seen IPs\n| join kind=leftanti (nxDomainDnsEvents (stime=ago(lookback), etime=ago(referenceendtime))\n | summarize DNSQueryCount=dcount(DnsQuery) by SrcIpAddr\n | where DNSQueryCount > toscalar(threshold))\n on SrcIpAddr\n// Pull out sample NXDomain responses for those remaining potentially infected IPs\n| join kind = inner (nxDomainDnsEvents (stime=ago(lookback), etime=now())\n | summarize by DnsQuery, SrcIpAddr)\n on SrcIpAddr\n| summarize\n StartTimeUtc = min(StartTimeUtc),\n EndTimeUtc = max(EndTimeUtc),\n DNSQueries=make_list(DnsQuery, 100)\n by SrcIpAddr, DNSQueryCount\n| extend DNSQueryThreshold=toint(toscalar(threshold))\n",
"queryFrequency": "P1D",
"queryPeriod": "P10D",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0,
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"CommandAndControl"
],
"techniques": [
"T1568",
"T1008"
],
"alertRuleTemplateName": "89ba52fa-96a7-4653-829a-ca49bb13336c",
"eventGroupingSettings": {
"aggregationKind": "AlertPerResult"
},
"alertDetailsOverride": {
"alertDisplayNameFormat": "[Static threshold] Potential DGA (Domain Generation Algorithm) originating from client IP: '{{SrcIpAddr}}' has been detected.",
"alertDescriptionFormat": "Client has been identified with high NXDomain count which could be indicative of a DGA (cycling through possible C2 domains where most C2s are not live). This client is found to be communicating with multiple Domains which do not exist.\n\nDGA DNS query count baseline is: '{{DNSQueryThreshold}}'\n\nCurrent failed DNS query count from this client: '{{DNSQueryCount}}'\n\nDNS queries requested by this client inlcude: '{{DNSQueries}}'"
},
"customDetails": {
"DNSQueryCount": "DNSQueryCount",
"DNSQueries": "DNSQueries",
"DNSQueryThreshold": "DNSQueryThreshold"
},
"entityMappings": [
{
"entityType": "IP",
"fieldMappings": [
{
"identifier": "Address",
"columnName": "SrcIpAddr"
}
]
}
],
"status": "Available",
"templateVersion": "1.0.0",
"tags": [
{
"Schema": "ASimDns",
"SchemaVersion": "0.1.6"
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/PotentialDGADetectedviaRepetitiveFailuresStaticThresholdBased.yaml"
}
}
]
}