Detection rules › Sigma

Notepad++ Updater DNS Query to Uncommon Domains

Severity
medium
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Source
upstream

Detects when the Notepad++ updater (gup.exe) makes DNS queries to domains that are not part of the known legitimate update infrastructure. This could indicate potential exploitation of the updater mechanism or suspicious network activity that warrants further investigation.

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1195.002 Supply Chain Compromise: Compromise Software Supply Chain
Credential AccessT1557 Adversary-in-the-Middle
CollectionT1557 Adversary-in-the-Middle

Event coverage

ProviderEvent IDTitle
Sysmon22DNSEvent (DNS query)

Stages and Predicates

Stage 1: selection

Image|endswith: '\gup.exe'

Stage 2: not 1 of filter_main_notepad_legit_domain

QueryName: notepad-plus-plus.org

Stage 3: not 1 of filter_optional_*

or:
QueryName|endswith: .azurewebsites.net
QueryName|endswith: .githubusercontent.com
QueryName|endswith: .googleapis.com
QueryName|endswith: .sourceforge.net
QueryName|endswith: block.opendns.com
QueryName|endswith: gateway.zscalerthree.net
QueryName: github.com

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.

FieldKindValues
Imageends_with
  • \gup.exe corpus 3 (sigma 3)
QueryNameends_with
  • .azurewebsites.net
  • .githubusercontent.com
  • .googleapis.com
  • .sourceforge.net
  • block.opendns.com
  • gateway.zscalerthree.net
QueryNameeq
  • github.com
  • notepad-plus-plus.org