Detection rules › Sigma

Renamed Microsoft Teams Execution

Status
test
Severity
medium
Log source
category process_creation, product windows
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the execution of a renamed Microsoft Teams binary.

MITRE ATT&CK coverage

TacticTechniques
StealthNo specific technique

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 1: Process creation

Rule body

title: Renamed Microsoft Teams Execution
id: 88f46b67-14d4-4f45-ac2c-d66984f22191
status: test
description: Detects the execution of a renamed Microsoft Teams binary.
references:
    - Internal Research
author: Nasreddine Bencherchali (Nextron Systems)
date: 2024-07-12
tags:
    - attack.stealth
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        OriginalFileName:
            - 'msteams.exe'
            - 'teams.exe'
    filter_main_legit_names:
        Image|endswith:
            - '\msteams.exe'
            - '\teams.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    OriginalFileName:
        - 'msteams.exe'
        - 'teams.exe'

Stage 2: not filter_main_legit_names

filter_main_legit_names:
    Image|endswith:
        - '\msteams.exe'
        - '\teams.exe'

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
Imageends_with\msteams.exeexcludes:Image field:"Image" value:"\msteams.exe"
Imageends_with\teams.exeexcludes:Image field:"Image" value:"\teams.exe"

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
OriginalFileNameeq
  • msteams.exe corpus 2 (sigma 2)
  • teams.exe corpus 2 (sigma 2)
field:"OriginalFileName" kind:eq