Cyber: Notepad++ Hosting Breach Attributed To China-linked Lotus Blossom...

A China-linked threat actor known as Lotus Blossom has been attributed with medium confidence to the recently discovered compromise of the infrastructure hosting Notepad++.

The attack enabled the state-sponsored hacking group to deliver a previously undocumented backdoor codenamed Chrysalis to users of the open-source editor, according to new findings from Rapid7.

The development comes shortly after Notepad++ maintainer Don Ho said that a compromise at the hosting provider level allowed threat actors to hijack update traffic starting June 2025 and selectively redirect such requests from certain users to malicious servers to serve a tampered update by exploiting insufficient update verification controls that existed in older versions of the utility.

The weakness was plugged in December 2025 with the release of version 8.8.9. It has since emerged that the hosting provider for the software was breached to perform targeted traffic redirections until December 2, 2025, when the attacker's access was terminated. Notepad++ has since migrated to a new hosting provider with stronger security and rotated all credentials.

Rapid7's analysis of the incident has uncovered no evidence or artifacts to suggest that the updater-related mechanism was exploited to distribute malware.

"The only confirmed behavior is that execution of 'notepad++.exe' and subsequently 'GUP.exe' preceded the execution of a suspicious process 'update.exe' which was downloaded from 95.179.213.0," security researcher Ivan Feigl said.

"update.exe" is a Nullsoft Scriptable Install System (NSIS) installer that contains multiple files -

Chrysalis is a bespoke, feature-rich implant that gathers system information and contacts an external server ("api.skycloudcenter[.]com") to likely receive additional commands for execution on the infected host.

The command-and-control (C2) server is currently offline. However, a deeper examination of the obfuscated artifact has revealed that it's capable of processing incoming HTTP responses to spawn an interactive shell, create processes, perform file operations, upload/download files, and uninstall itself.

"Overall, the sample looks like something that has been actively developed over time," Rapid7 said, adding it also identified a file named "conf.c" that's designed to retrieve a Cobalt Strike beacon by means of a custom loader that embeds Metasploit block API shellcode.

Source: The Hacker News