OneNote.EXE Execution of Malicious Embedded Scripts

Severity: high
Author: @kostastsale
Source: upstream

Detects the execution of malicious OneNote documents that contain embedded scripts. When a user clicks on a OneNote attachment and then on the malicious link inside the ".one" file, it exports and executes the malicious embedded script from specific directories.

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1218.001` System Binary Proxy Execution: Compiled HTML File

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation
Security-Auditing	4688	A new process has been created.

Stages and Predicates

Stage 1: `selection`

or:
CommandLine|contains: '\exported\'
CommandLine|contains: '\onenoteofflinecache_files\'
or:
Image|endswith: '\cmd.exe'
Image|endswith: '\cscript.exe'
Image|endswith: '\mshta.exe'
Image|endswith: '\powershell.exe'
Image|endswith: '\pwsh.exe'
Image|endswith: '\wscript.exe'
ParentImage|endswith: '\onenote.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.