Detection rules › Kusto Query Language

Rare client observed with high reverse DNS lookup count - Static threshold based (ASIM DNS Solution)

Source
upstream

'This rule identifies clients with high reverse DNS counts, which could be carrying out reconnaissance or discovery activity. This helps in detecting the possible initial phases of an attack, like discovery and reconnaissance. It utilizes ASIM normalization and is applied to any source that supports the ASIM DNS schema.'

MITRE ATT&CK coverage

TacticTechniques
ReconnaissanceT1590 Gather Victim Network Information

Event coverage

ProviderEvent IDTitle
Sysmon22DNSEvent (DNS query)

Stages and Predicates

Stage 1: source

_Im_Dns

Stage 2: summarize

Stage 3: where

DNSQueryCount gt "threshold"

Stage 4: project

Stage 5: join

Stage 6: join

Stage 7: extend

Stage 8: project-away

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
DNSQueryCountgt
  • threshold