The developer of the popular open source text editor Notepad++ has confirmed that hackers hijacked the software to deliver malicious updates to users over the course of several months in 2025.

In a blog post published Monday, Notepad++ developer Don Ho said that the cyberattack was likely carried out by hackers associated with the Chinese government between June and December 2025, citing multiple analyses by security experts who examined the malware payloads and attack patterns. Ho said this “would explain the highly selective targeting” seen during the campaign.