Potentially Suspicious Command Targeting Teams Sensitive Files — Sigma Rule

Rule metadata and linked tags

Author: @SerkinValery. Source status: test; severity: medium. Source dates: 2022-09-16 / 2023-12-18.

{
  "product": "windows",
  "category": "process_creation"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 8d3023810f3564d8173669818d0e7072a9f6663ad5d2ba5ef4e57bc452a3dd35

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Potentially Suspicious Command Targeting Teams Sensitive Files
id: d2eb17db-1d39-41dc-b57f-301f6512fa75
status: test
description: |
    Detects a commandline containing references to the Microsoft Teams database or cookies files from a process other than Teams.
    The database might contain authentication tokens and other sensitive information about the logged in accounts.
references:
    - https://www.bleepingcomputer.com/news/security/microsoft-teams-stores-auth-tokens-as-cleartext-in-windows-linux-macs/
    - https://www.vectra.ai/blogpost/undermining-microsoft-teams-security-by-mining-tokens
author: '@SerkinValery'
date: 2022-09-16
modified: 2023-12-18
tags:
    - attack.credential-access
    - attack.t1528
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        CommandLine|contains:
            - '\Microsoft\Teams\Cookies'
            - '\Microsoft\Teams\Local Storage\leveldb'
    filter_main_legit_locations:
        Image|endswith: '\Microsoft\Teams\current\Teams.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.bleepingcomputer.com/news/security/microsoft-teams-stores-auth-tokens-as-cleartext-in-windows-linux-macs/
• https://www.vectra.ai/blogpost/undermining-microsoft-teams-security-by-mining-tokens