↳ GitHub sourceAnalytics ruleHigh

Cisco SEG - Unexpected attachment

View on GitHub ↗Original file ↗

Description

'Detects possibly malicious attachments.'

Rule type: Scheduled
Version: 1.0.3
Declared status: Available
Query frequency: 1h
Query period: 1h
Trigger: gt 0

Declared MITRE coverage

InitialAccess T1566

Declared sources

Metadata from the source file. No dependencies inferred from KQL.

Connectors

CefAma

Data types

CommonSecurityLog

KQL query

Original query, unchanged.

CiscoSEGEvent
| where NetworkDirection =~ 'Incoming'
| where tostring(AdditionalFields) has 'ESAAttachmentDetails'
| extend attachment = replace_string(tostring(extract(@'"ESAAttachmentDetails":"{(.*?):', 1, tostring(AdditionalFields))), "'", "")
| where attachment endswith '.ps1' or attachment endswith '.lnk' or attachment endswith '.exe'
| extend AccountCustomEntity = DstUserName

Declared entities

Account

Source provenance

GitHub

Displayed values come from files in Azure/Azure-Sentinel. They describe the published template, not your workspace configuration.

File: Solutions/CiscoSEG/Analytic Rules/CiscoSEGUnexpectedAttachment.yaml ↗
Commit: 9800e51 ↗
Source identifier: f8ba18c4-81e3-4db0-8f85-4989f2ed2ade

Additional source files 2

Solutions/CiscoSEG/Analytic Rules/CiscoSEGUnexpectedAttachment.yamlsource ↗Solutions/CiscoSEG/Data/Solution_CiscoSEG.jsonsolution-membership ↗

GSTEP / CATALOG TRACKING

Added to catalog : 16 Sept 2026 · 05:49 UTC
Last change observed : 16 Sept 2026 · 05:49 UTC

GSTEP sync dates, separate from the source content’s publication dates.