Potential DGA(Domain Generation Algorithm) detected via Repetitive Failures - Anomaly based (ASIM DNS Solution)
| Id | 01191239-274e-43c9-b154-3a042692af06 |
| Rulename | Potential DGA(Domain Generation Algorithm) detected via Repetitive Failures - Anomaly based (ASIM DNS Solution) |
| Description | This rule makes use of the series decompose anomaly method to detect clients with a high NXDomain response count, which could be indicative of a DGA (cycling through possible C2 domains where most C2s are not live). An alert is generated when new IP address DNS activity is identified as an outlier when compared to the baseline, indicating a recurring pattern. \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 | 14d |
| Trigger threshold | 0 |
| Trigger operator | gt |
| Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/PotentialDGADetectedviaRepetitiveFailuresAnomalyBased.yaml |
| Version | 1.0.0 |
| Arm template | 01191239-274e-43c9-b154-3a042692af06.json |
let threshold = materialize (_GetWatchlist('DNS_Solution_Monitoring_Configuration')
| where wl_RuleName == 'Anomaly - Potential DGA(Domain Generation Algorithm) detected'
and wl_Type == 'Detection'
| project todouble(wl_AnomalyThreshold));
let min_t = ago(14d);
let max_t = now();
let timeframe = 1d;
// calculate avg. eps(events per second)
let eps = materialize (_Im_Dns
| project TimeGenerated
| where TimeGenerated > ago(5m)
| count
| extend Count = Count / 300);
let maxSummarizedTime = toscalar (
union isfuzzy=true
(
DNS_Summarized_Logs_ip_CL
| where EventTime_t >= min_t
| summarize max_TimeGenerated=max(EventTime_t)
| extend max_TimeGenerated = datetime_add('hour', 1, max_TimeGenerated)
),
(
print(min_t)
| project max_TimeGenerated = print_0
)
| summarize maxTimeGenerated = max(max_TimeGenerated)
);
let summarizationexist = materialize(
union isfuzzy=true
(
DNS_Summarized_Logs_ip_CL
| where EventTime_t > ago(1d)
| project v = int(2)
),
(
print int(1)
| project v = print_0
)
| summarize maxv = max(v)
| extend sumexist = (maxv > 1)
);
let allData = union isfuzzy=true
(
(datatable(exists: int, sumexist: bool)[1, false]
| where toscalar(eps) > 1000
| join (summarizationexist) on sumexist)
| join (
_Im_Dns(responsecodename='NXDOMAIN', starttime=todatetime(ago(2d)), endtime=now())
| where TimeGenerated > maxSummarizedTime
| summarize Count=count() by SrcIpAddr, DnsQuery, bin(TimeGenerated, 1h)
| extend EventTime = TimeGenerated, Count = toint(Count), exists=int(1)
)
on exists
| project-away exists, maxv, sum*
),
(
(datatable(exists: int, sumexist: bool)[1, false]
| where toscalar(eps) between (501 .. 1000)
| join (summarizationexist) on sumexist)
| join (
_Im_Dns(responsecodename='NXDOMAIN', starttime=todatetime(ago(3d)), endtime=now())
| where TimeGenerated > maxSummarizedTime
| summarize Count=count() by SrcIpAddr, DnsQuery, bin(TimeGenerated, 1h)
| extend EventTime = TimeGenerated, Count = toint(Count), exists=int(1)
)
on exists
| project-away exists, maxv, sum*
),
(
(datatable(exists: int, sumexist: bool)[1, false]
| where toscalar(eps) <= 500
| join (summarizationexist) on sumexist)
| join (
_Im_Dns(responsecodename='NXDOMAIN', starttime=todatetime(ago(4d)), endtime=now())
| where TimeGenerated > maxSummarizedTime
| summarize Count=count() by SrcIpAddr, DnsQuery, bin(TimeGenerated, 1h)
| extend EventTime = TimeGenerated, Count = toint(Count), exists=int(1)
)
on exists
| project-away exists, maxv, sum*
),
(
DNS_Summarized_Logs_ip_CL
| where EventTime_t > min_t and EventResultDetails_s == 'NXDOMAIN'
| project-rename
SrcIpAddr=SrcIpAddr_s,
DnsQuery=DnsQuery_s,
Count=count__d,
EventTime=EventTime_t
| extend Count = toint(Count)
);
allData
| make-series QueryCount=dcount(DnsQuery) on EventTime from min_t to max_t step timeframe by SrcIpAddr
// include calculated Anomalies, Score and Baseline
| extend (anomalies, score, baseline) = series_decompose_anomalies(QueryCount, toscalar(threshold), -1, 'linefit')
| mv-expand anomalies, score, baseline, EventTime, QueryCount
| extend
anomalies = toint(anomalies),
score = toint(score),
baseline = toint(baseline),
EventTime = todatetime(EventTime),
Total = tolong(QueryCount)
| where EventTime >= ago(timeframe)
| where score >= (toscalar(threshold) * 2)
// Join the allData to include DnsQuery details
| join kind=inner(allData
| where TimeGenerated >= ago(timeframe)
| summarize DNSQueries = make_set(DnsQuery, 1000) by SrcIpAddr)
on SrcIpAddr
| project-away SrcIpAddr1
tactics:
- CommandAndControl
severity: Medium
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
triggerOperator: gt
eventGroupingSettings:
aggregationKind: AlertPerResult
alertDetailsOverride:
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.
Baseline Domain or DNS query count from this client: '{{baseline}}'
Current Domain or DNS query count from this client: '{{Total}}'
DNS queries requested by this client inlcude: '{{DNSQueries}}'
alertDisplayNameFormat: "[Anomaly] Potential DGA (Domain Generation Algorithm) originating from client IP: '{{SrcIpAddr}}' has been detected."
query: |
let threshold = materialize (_GetWatchlist('DNS_Solution_Monitoring_Configuration')
| where wl_RuleName == 'Anomaly - Potential DGA(Domain Generation Algorithm) detected'
and wl_Type == 'Detection'
| project todouble(wl_AnomalyThreshold));
let min_t = ago(14d);
let max_t = now();
let timeframe = 1d;
// calculate avg. eps(events per second)
let eps = materialize (_Im_Dns
| project TimeGenerated
| where TimeGenerated > ago(5m)
| count
| extend Count = Count / 300);
let maxSummarizedTime = toscalar (
union isfuzzy=true
(
DNS_Summarized_Logs_ip_CL
| where EventTime_t >= min_t
| summarize max_TimeGenerated=max(EventTime_t)
| extend max_TimeGenerated = datetime_add('hour', 1, max_TimeGenerated)
),
(
print(min_t)
| project max_TimeGenerated = print_0
)
| summarize maxTimeGenerated = max(max_TimeGenerated)
);
let summarizationexist = materialize(
union isfuzzy=true
(
DNS_Summarized_Logs_ip_CL
| where EventTime_t > ago(1d)
| project v = int(2)
),
(
print int(1)
| project v = print_0
)
| summarize maxv = max(v)
| extend sumexist = (maxv > 1)
);
let allData = union isfuzzy=true
(
(datatable(exists: int, sumexist: bool)[1, false]
| where toscalar(eps) > 1000
| join (summarizationexist) on sumexist)
| join (
_Im_Dns(responsecodename='NXDOMAIN', starttime=todatetime(ago(2d)), endtime=now())
| where TimeGenerated > maxSummarizedTime
| summarize Count=count() by SrcIpAddr, DnsQuery, bin(TimeGenerated, 1h)
| extend EventTime = TimeGenerated, Count = toint(Count), exists=int(1)
)
on exists
| project-away exists, maxv, sum*
),
(
(datatable(exists: int, sumexist: bool)[1, false]
| where toscalar(eps) between (501 .. 1000)
| join (summarizationexist) on sumexist)
| join (
_Im_Dns(responsecodename='NXDOMAIN', starttime=todatetime(ago(3d)), endtime=now())
| where TimeGenerated > maxSummarizedTime
| summarize Count=count() by SrcIpAddr, DnsQuery, bin(TimeGenerated, 1h)
| extend EventTime = TimeGenerated, Count = toint(Count), exists=int(1)
)
on exists
| project-away exists, maxv, sum*
),
(
(datatable(exists: int, sumexist: bool)[1, false]
| where toscalar(eps) <= 500
| join (summarizationexist) on sumexist)
| join (
_Im_Dns(responsecodename='NXDOMAIN', starttime=todatetime(ago(4d)), endtime=now())
| where TimeGenerated > maxSummarizedTime
| summarize Count=count() by SrcIpAddr, DnsQuery, bin(TimeGenerated, 1h)
| extend EventTime = TimeGenerated, Count = toint(Count), exists=int(1)
)
on exists
| project-away exists, maxv, sum*
),
(
DNS_Summarized_Logs_ip_CL
| where EventTime_t > min_t and EventResultDetails_s == 'NXDOMAIN'
| project-rename
SrcIpAddr=SrcIpAddr_s,
DnsQuery=DnsQuery_s,
Count=count__d,
EventTime=EventTime_t
| extend Count = toint(Count)
);
allData
| make-series QueryCount=dcount(DnsQuery) on EventTime from min_t to max_t step timeframe by SrcIpAddr
// include calculated Anomalies, Score and Baseline
| extend (anomalies, score, baseline) = series_decompose_anomalies(QueryCount, toscalar(threshold), -1, 'linefit')
| mv-expand anomalies, score, baseline, EventTime, QueryCount
| extend
anomalies = toint(anomalies),
score = toint(score),
baseline = toint(baseline),
EventTime = todatetime(EventTime),
Total = tolong(QueryCount)
| where EventTime >= ago(timeframe)
| where score >= (toscalar(threshold) * 2)
// Join the allData to include DnsQuery details
| join kind=inner(allData
| where TimeGenerated >= ago(timeframe)
| summarize DNSQueries = make_set(DnsQuery, 1000) by SrcIpAddr)
on SrcIpAddr
| project-away SrcIpAddr1
triggerThreshold: 0
name: Potential DGA(Domain Generation Algorithm) detected via Repetitive Failures - Anomaly based (ASIM DNS Solution)
kind: Scheduled
version: 1.0.0
description: |
'This rule makes use of the series decompose anomaly method to detect clients with a high NXDomain response count, which could be indicative of a DGA (cycling through possible C2 domains where most C2s are not live). An alert is generated when new IP address DNS activity is identified as an outlier when compared to the baseline, indicating a recurring pattern. \n\nIt utilizes [ASIM](https://aka.ms/AboutASIM) normalization and is applied to any source that supports the ASIM DNS schema.'
relevantTechniques:
- T1568
- T1008
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/PotentialDGADetectedviaRepetitiveFailuresAnomalyBased.yaml
customDetails:
Total: Total
AnomalyScore: score
baseline: baseline
DNSQueries: DNSQueries
tags:
- Schema: ASimDns
SchemaVersion: 0.1.6
status: Available
queryFrequency: 1d
queryPeriod: 14d
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: SrcIpAddr
id: 01191239-274e-43c9-b154-3a042692af06
{
"$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/01191239-274e-43c9-b154-3a042692af06')]",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/01191239-274e-43c9-b154-3a042692af06')]",
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
"kind": "Scheduled",
"apiVersion": "2022-11-01",
"properties": {
"displayName": "Potential DGA(Domain Generation Algorithm) detected via Repetitive Failures - Anomaly based (ASIM DNS Solution)",
"description": "'This rule makes use of the series decompose anomaly method to detect clients with a high NXDomain response count, which could be indicative of a DGA (cycling through possible C2 domains where most C2s are not live). An alert is generated when new IP address DNS activity is identified as an outlier when compared to the baseline, indicating a recurring pattern. \\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 == 'Anomaly - Potential DGA(Domain Generation Algorithm) detected'\n and wl_Type == 'Detection'\n | project todouble(wl_AnomalyThreshold));\nlet min_t = ago(14d);\nlet max_t = now();\nlet timeframe = 1d;\n// calculate avg. eps(events per second)\nlet eps = materialize (_Im_Dns\n | project TimeGenerated\n | where TimeGenerated > ago(5m)\n | count\n | extend Count = Count / 300);\nlet maxSummarizedTime = toscalar (\n union isfuzzy=true \n (\n DNS_Summarized_Logs_ip_CL \n | where EventTime_t >= min_t\n | summarize max_TimeGenerated=max(EventTime_t)\n | extend max_TimeGenerated = datetime_add('hour', 1, max_TimeGenerated)\n ),\n (\n print(min_t)\n | project max_TimeGenerated = print_0\n )\n | summarize maxTimeGenerated = max(max_TimeGenerated) \n );\nlet summarizationexist = materialize(\n union isfuzzy=true \n (\n DNS_Summarized_Logs_ip_CL\n | where EventTime_t > ago(1d) \n | project v = int(2)\n ),\n (\n print int(1) \n | project v = print_0\n )\n | summarize maxv = max(v)\n | extend sumexist = (maxv > 1)\n );\nlet allData = union isfuzzy=true\n (\n (datatable(exists: int, sumexist: bool)[1, false]\n | where toscalar(eps) > 1000\n | join (summarizationexist) on sumexist)\n | join (\n _Im_Dns(responsecodename='NXDOMAIN', starttime=todatetime(ago(2d)), endtime=now())\n | where TimeGenerated > maxSummarizedTime\n | summarize Count=count() by SrcIpAddr, DnsQuery, bin(TimeGenerated, 1h)\n | extend EventTime = TimeGenerated, Count = toint(Count), exists=int(1)\n )\n on exists\n | project-away exists, maxv, sum*\n ),\n (\n (datatable(exists: int, sumexist: bool)[1, false]\n | where toscalar(eps) between (501 .. 1000)\n | join (summarizationexist) on sumexist)\n | join (\n _Im_Dns(responsecodename='NXDOMAIN', starttime=todatetime(ago(3d)), endtime=now())\n | where TimeGenerated > maxSummarizedTime\n | summarize Count=count() by SrcIpAddr, DnsQuery, bin(TimeGenerated, 1h)\n | extend EventTime = TimeGenerated, Count = toint(Count), exists=int(1)\n )\n on exists\n | project-away exists, maxv, sum*\n ),\n (\n (datatable(exists: int, sumexist: bool)[1, false]\n | where toscalar(eps) <= 500\n | join (summarizationexist) on sumexist)\n | join (\n _Im_Dns(responsecodename='NXDOMAIN', starttime=todatetime(ago(4d)), endtime=now())\n | where TimeGenerated > maxSummarizedTime\n | summarize Count=count() by SrcIpAddr, DnsQuery, bin(TimeGenerated, 1h)\n | extend EventTime = TimeGenerated, Count = toint(Count), exists=int(1)\n )\n on exists\n | project-away exists, maxv, sum*\n ),\n (\n DNS_Summarized_Logs_ip_CL\n | where EventTime_t > min_t and EventResultDetails_s == 'NXDOMAIN'\n | project-rename\n SrcIpAddr=SrcIpAddr_s,\n DnsQuery=DnsQuery_s,\n Count=count__d,\n EventTime=EventTime_t\n | extend Count = toint(Count)\n );\nallData\n| make-series QueryCount=dcount(DnsQuery) on EventTime from min_t to max_t step timeframe by SrcIpAddr\n// include calculated Anomalies, Score and Baseline\n| extend (anomalies, score, baseline) = series_decompose_anomalies(QueryCount, toscalar(threshold), -1, 'linefit')\n| mv-expand anomalies, score, baseline, EventTime, QueryCount\n| extend\n anomalies = toint(anomalies),\n score = toint(score),\n baseline = toint(baseline),\n EventTime = todatetime(EventTime),\n Total = tolong(QueryCount)\n| where EventTime >= ago(timeframe)\n| where score >= (toscalar(threshold) * 2)\n// Join the allData to include DnsQuery details\n| join kind=inner(allData\n | where TimeGenerated >= ago(timeframe)\n | summarize DNSQueries = make_set(DnsQuery, 1000) by SrcIpAddr)\n on SrcIpAddr\n| project-away SrcIpAddr1\n",
"queryFrequency": "P1D",
"queryPeriod": "P14D",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0,
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"CommandAndControl"
],
"techniques": [
"T1568",
"T1008"
],
"alertRuleTemplateName": "01191239-274e-43c9-b154-3a042692af06",
"eventGroupingSettings": {
"aggregationKind": "AlertPerResult"
},
"alertDetailsOverride": {
"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\nBaseline Domain or DNS query count from this client: '{{baseline}}'\n\nCurrent Domain or DNS query count from this client: '{{Total}}'\n\nDNS queries requested by this client inlcude: '{{DNSQueries}}'",
"alertDisplayNameFormat": "[Anomaly] Potential DGA (Domain Generation Algorithm) originating from client IP: '{{SrcIpAddr}}' has been detected."
},
"customDetails": {
"Total": "Total",
"AnomalyScore": "score",
"baseline": "baseline",
"DNSQueries": "DNSQueries"
},
"entityMappings": [
{
"fieldMappings": [
{
"columnName": "SrcIpAddr",
"identifier": "Address"
}
],
"entityType": "IP"
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/PotentialDGADetectedviaRepetitiveFailuresAnomalyBased.yaml",
"templateVersion": "1.0.0",
"status": "Available",
"tags": [
{
"Schema": "ASimDns",
"SchemaVersion": "0.1.6"
}
]
}
}
]
}