Renamed Microsoft Teams Execution

Severity: medium
Author: Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects the execution of a renamed Microsoft Teams binary.

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `selection`

OriginalFileName: [msteams.exe, teams.exe]

Stage 2: `not 1 of filter_main_legit_names`

or:
Image|endswith: '\msteams.exe'
Image|endswith: '\teams.exe'

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.

Field	Kind	Values
`Image`	ends_with	`\msteams.exe` corpus 3 (sigma 3) `\teams.exe` corpus 2 (sigma 2)
`OriginalFileName`	eq	`msteams.exe` corpus 2 (sigma 2) `teams.exe`