A sophisticated cyber attack has been discovered that compromised the update infrastructure for Notepad++, a widely used free source code editor and note-taking app for Windows. The attackers, suspected to be state-backed hackers from China, successfully delivered a backdoored version of the app to select targets, compromising their security.
The attack began in June with an "infrastructure-level compromise" that allowed malicious actors to intercept and redirect update traffic destined for notepad-plus-plus.org. Once inside, the attackers selectively redirected certain targeted users to malicious update servers where they received compromised updates. Notepad++ didn't regain control of its infrastructure until December.
Security firm Rapid 7 described a never-before-seen payload dubbed Chrysalis as a "custom, feature-rich backdoor" that was installed by the attackers. The researchers noted that Chrysalis is a sophisticated tool with a wide array of capabilities, indicating it's a permanent and powerful hacking instrument rather than a simple throwaway utility.
The attackers specifically targeted Notepad++ domain with the goal of exploiting insufficient update verification controls in older versions of the app. They tried to re-exploit one of the weaknesses after it was fixed but failed.
Independent researcher Kevin Beaumont warned that devices with Notepad++ installed experienced "security incidents" resulting from hackers taking direct control using a web-based interface. Three organizations, all with interests in East Asia, confirmed that they were affected by these security incidents.
Beaumont advised users to ensure they're running the official version 8.8.8 or higher installed manually from notepad-plus-plus.org, and recommended larger organizations block Notepad++ updates or the gup.exe process from having internet access.
In recent months, Microsoft has integrated Copilot AI into Notepad, drawing even more interest in the app. However, like many open-source projects, funding for Notepad++ is dwarfed by its reliance on it, leaving vulnerabilities that could have been caught and fixed with sufficient resources.
The attack began in June with an "infrastructure-level compromise" that allowed malicious actors to intercept and redirect update traffic destined for notepad-plus-plus.org. Once inside, the attackers selectively redirected certain targeted users to malicious update servers where they received compromised updates. Notepad++ didn't regain control of its infrastructure until December.
Security firm Rapid 7 described a never-before-seen payload dubbed Chrysalis as a "custom, feature-rich backdoor" that was installed by the attackers. The researchers noted that Chrysalis is a sophisticated tool with a wide array of capabilities, indicating it's a permanent and powerful hacking instrument rather than a simple throwaway utility.
The attackers specifically targeted Notepad++ domain with the goal of exploiting insufficient update verification controls in older versions of the app. They tried to re-exploit one of the weaknesses after it was fixed but failed.
Independent researcher Kevin Beaumont warned that devices with Notepad++ installed experienced "security incidents" resulting from hackers taking direct control using a web-based interface. Three organizations, all with interests in East Asia, confirmed that they were affected by these security incidents.
Beaumont advised users to ensure they're running the official version 8.8.8 or higher installed manually from notepad-plus-plus.org, and recommended larger organizations block Notepad++ updates or the gup.exe process from having internet access.
In recent months, Microsoft has integrated Copilot AI into Notepad, drawing even more interest in the app. However, like many open-source projects, funding for Notepad++ is dwarfed by its reliance on it, leaving vulnerabilities that could have been caught and fixed with sufficient resources.