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Potential DGA detected

Description

'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). Alerts are generated when a new IP address is seen (based on not being associated with NXDomain records in the prior 10-day baseline period).'
Type de règle
Scheduled
Version
1.0.3
Statut déclaré
Available
Fréquence
1d
Période analysée
10d
Déclenchement
gt 0

Couverture MITRE déclarée

Sources déclarées

Métadonnées du fichier source. Aucune dépendance déduite du KQL.

Connecteurs

Types de données

Requête KQL

Requête originale, sans modification.

let starttime = 10d;
let endtime = 1d;
let threshold = 100;
let nxDomainDnsEvents = DnsEvents
// ResultCode 3 => 'NXDOMAIN'
| where ResultCode == 3
| where QueryType in~ ("A", "AAAA")
| where ipv4_is_match("127.0.0.1", ClientIP) == False
| where Name !has "/"
| where Name has ".";
nxDomainDnsEvents
| where TimeGenerated > ago(endtime)
// sld = Second Level Domain
| extend sld = tostring(split(Name, ".")[-2])
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), dcount(sld), sampleNXDomainList=make_set(Name, 100) by ClientIP
| where dcount_sld > threshold
// Filter out previously seen IPs
// Returns all the records from the left side that don't have matches from the right
| join kind=leftanti (nxDomainDnsEvents
    | where TimeGenerated between(ago(starttime)..ago(endtime))
    | extend sld = tostring(split(Name, ".")[-2])
    | summarize dcount(sld) by ClientIP, bin(TimeGenerated,1d)
    | where dcount_sld > threshold
    ) on ClientIP
    | order by dcount_sld desc

Entités déclarées

IP

Contenus associés

Liens établis à partir des identifiants déclarés et des manifests des solutions.

Traçabilité de la source

GitHub

Les valeurs affichées proviennent des fichiers du dépôt Azure/Azure-Sentinel. Elles décrivent le modèle publié, pas la configuration de votre workspace.

Identifiant source
a0907abe-6925-4d90-af2b-c7e89dc201a6
Autres fichiers source 3Solutions/Windows Server DNS/Analytic Rules/DNS_HighNXDomainCount_detection.yamlsource ↗Detections/DnsEvents/DNS_HighNXDomainCount_detection.yamlmigration-note ↗Solutions/Windows Server DNS/Data/Solution_DNS.jsonsolution-membership ↗
GSTEP / SUIVI DU CATALOGUE

Ajouté au catalogue : 16 sept. 2026 · 05:49 UTC
Dernier changement observé : 16 sept. 2026 · 05:49 UTC

Dates de synchronisation GSTEP, distinctes des dates de publication du contenu source.