A supply‑chain compromise affecting Notepad++’s official update infrastructure allowed threat actors to redirect some users to attacker‑controlled downloads, potentially leading to malware delivery and code execution on affected endpoints. Read this Cybersecurity Threat Advisory to learn more and understand how to mitigate your risk.
What is the threat?
Threat actors compromised Notepad++’s update distribution path and supporting hosting infrastructure, allowing them to redirect users to attacker‑controlled downloads. This activity could result in trojanized installers or other malicious payloads that enable endpoint compromise and code execution after installation.
Following the discovery, the Notepad++ team migrated its website to a new hosting provider with stronger security controls and reinforced the update delivery process with additional safeguards to ensure the integrity and safety of future updates.
Why is it noteworthy?
By compromising Notepad++’s infrastructure, threat actors abused a trusted software distribution path, allowing them to redirect users to attacker‑controlled downloads and potentially deliver malware during routine update activity.
Because the primary trigger is normal user or administrator behavior—accepting and installing updates—the activity can be difficult to detect and may scale quickly if the compromised redirect or hosting infrastructure impacts a large user base. Reporting also links the activity to a hosting‑level breach, underscoring the broader supply‑chain risk that a single upstream compromise can cascade across many downstream environments.
What is the exposure or risk?
The primary exposure in this Notepad++ supply‑chain incident is malware delivery through a trusted update and download path. Since attackers rely on legitimate update behavior rather than exploiting a specific application vulnerability, the practical risk hinges on which users accessed malicious infrastructure and whether they executed the malicious download.
Organizations that widely deploy Notepad++ or routinely perform updates from official channels may face elevated risk.
What are the recommendations?
Barracuda recommends the following mitigation steps to prevent this threat from impacting your environment:
- Update Notepad++ to v8.9.1 using a manual download from the official project site or release location. Avoid in‑app or automated update prompts until you have confirmed the update path is trusted.
- Temporarily disable or restrict auto‑update and “check for updates” functionality, and force updates through managed software distribution tools (e.g., SCCM, Intune, Jamf, or an internal package repository) to prevent endpoints from independently downloading installers from the internet.
- Validate publisher signatures and/or known‑good file hashes before packaging or deploying Notepad++. Ensure all downloads originate from approved domains using proxy allow‑listing.
- Preserve proxy, DNS, and firewall logs for endpoints that attempted Notepad++ updates or downloads. Triage affected hosts for recent Notepad++ installer execution, unexpected child processes, persistence mechanisms, and newly created or unknown binaries around the update attempt time window.
References
For more in-depth information about the recommendations, please visit the following links:
- https://thehackernews.com/2026/02/notepad-hosting-breach-attributed-to.html
- https://thehackernews.com/2026/02/notepad-official-update-mechanism.html
- https://orca.security/resources/blog/notepad-plus-plus-supply-chain-attack/
If you have any questions about this Cybersecurity Threat Advisory, don’t hesitate to get in touch with Barracuda Managed XDR’s Security Operations Center.
This post originally appeared on Smarter MSP.