Detection rules › Sigma
OneNote Attachment File Dropped In Suspicious Location
Detects creation of files with the ".one"/".onepkg" extension in suspicious or uncommon locations. This could be a sign of attackers abusing OneNote attachments
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | No specific technique |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 11 | FileCreate |
Rule body yaml
title: OneNote Attachment File Dropped In Suspicious Location
id: 7fd164ba-126a-4d9c-9392-0d4f7c243df0
status: test
description: Detects creation of files with the ".one"/".onepkg" extension in suspicious or uncommon locations. This could be a sign of attackers abusing OneNote attachments
references:
- https://www.bleepingcomputer.com/news/security/hackers-now-use-microsoft-onenote-attachments-to-spread-malware/
- https://blog.osarmor.com/319/onenote-attachment-delivers-asyncrat-malware/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-01-22
modified: 2023-09-19
tags:
- attack.stealth
logsource:
category: file_event
product: windows
detection:
selection:
TargetFilename|contains:
# Note: add more common locations for drops such as download folders and the like. Or baseline legitimate locations and alert on everything else
- '\AppData\Local\Temp\'
- '\Users\Public\'
- '\Windows\Temp\'
- ':\Temp\'
TargetFilename|endswith:
- '.one'
- '.onepkg'
filter_main_onenote:
Image|contains: ':\Program Files\Microsoft Office\'
Image|endswith: '\ONENOTE.EXE'
condition: selection and not 1 of filter_main_*
falsepositives:
- Legitimate usage of ".one" or ".onepkg" files from those locations
level: medium
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_main_*Stage 1: selection
selection:
TargetFilename|contains:
- '\AppData\Local\Temp\'
- '\Users\Public\'
- '\Windows\Temp\'
- ':\Temp\'
TargetFilename|endswith:
- '.one'
- '.onepkg'
Stage 2: not filter_main_onenote
filter_main_onenote:
Image|contains: ':\Program Files\Microsoft Office\'
Image|endswith: '\ONENOTE.EXE'
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
Image | ends_with | \ONENOTE.EXE |
Image | match | :\Program Files\Microsoft Office\ |
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 |
|---|---|---|
TargetFilename | ends_with |
|
TargetFilename | match |
|