Arbitrary Binary Execution Using GUP Utility

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

Detects execution of the Notepad++ updater (gup) to launch other commands or executables

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`

Image|endswith: '\explorer.exe'
ParentImage|endswith: '\gup.exe'

Stage 2: `not 1 of filter*`

or:
CommandLine|contains: '\Notepad++\notepad++.exe'
Image|endswith: '\explorer.exe'
CommandLine: null
ParentImage|contains: '\Notepad++\updater\'

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
`CommandLine`	match	`\Notepad++\notepad++.exe`
`Image`	ends_with	`\explorer.exe` corpus 12 (sigma 12)
`ParentImage`	ends_with	`\gup.exe` corpus 2 (sigma 2)
`ParentImage`	match	`\Notepad++\updater\`

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.

Suspicious Child Process of Notepad++ Updater - GUP.Exe [sigma] (drops 1 filter this rule applies) (first-stage match only; downstream stages may differ)