Suspicious Download from Office Domain

testhigh

log source: windows · process_creationauthor Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)date 2021-12-27

description

What this is, in brief.

Detects suspicious ways to download files from Microsoft domains that are used to store attachments in Emails or OneNote documents

rule source (YAML)

title: Suspicious Download from Office Domain
id: 00d49ed5-4491-4271-a8db-650a4ef6f8c1
status: test
description: Detects suspicious ways to download files from Microsoft domains that are used to store attachments in Emails or OneNote documents
references:
    - https://twitter.com/an0n_r0/status/1474698356635193346?s=12
    - https://twitter.com/mrd0x/status/1475085452784844803?s=12
author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2021-12-27
modified: 2022-08-02
tags:
    - attack.command-and-control
    - attack.resource-development
    - attack.t1105
    - attack.t1608
logsource:
    product: windows
    category: process_creation
detection:
    selection_download:
        - Image|endswith:
              - '\curl.exe'
              - '\wget.exe'
        - CommandLine|contains:
              - 'Invoke-WebRequest'
              - 'iwr '
              - 'curl '
              - 'wget '
              - 'Start-BitsTransfer'
              - '.DownloadFile('
              - '.DownloadString('
    selection_domains:
        CommandLine|contains:
            - 'https://attachment.outlook.live.net/owa/'
            - 'https://onenoteonlinesync.onenote.com/onenoteonlinesync/'
    condition: all of selection_*
falsepositives:
    - Scripts or tools that download attachments from these domains (OneNote, Outlook 365)
level: high

detects techniques (2)

ATT&CK techniques this enables or maps to.

references

External citations — patches, advisories, analysis.