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For six months last year the update system of Notepad++, one of the world’s most widely used Windows text editors, was quietly subverted by hackers linked by investigators to the Chinese state. The attackers used their access not to disrupt the software openly, but to deliver malicious versions of it to carefully chosen targets.  According to a statement published this week on the project’s official website, the intrusion began in June with an infrastructure-level compromise that allowed attackers to intercept and redirect update traffic meant for notepad-plus-plus.org. Selected users were silently diverted to rogue update servers and served backdoored versions of the application. Control over the update infrastructure was not fully restored until December.  The developers said the attackers exploited weaknesses in how older versions of Notepad++ verified updates. By manipulating traffic between users and the update servers, they were able to substitute legitimate downloads with malicious ones.  Although update packages were signed, earlier design choices meant those signatures were not always robustly checked, creating an opening for tampering by a well-resourced adversary. Security researchers say the campaign was highly targeted.  The attackers installed a previously unknown backdoor, dubbed Chrysalis, which Rapid7 described as a custom and feature-rich tool designed for persistent access rather than short-term disruption. Such sophistication suggests strategic objectives rather than criminal opportunism.  Independent researcher Kevin Beaumont reported that several organisations with interests in East Asia experienced hands-on intrusions linked to compromised Notepad++ installations, indicating that attackers were able to take direct control of affected systems.  He had raised concerns months earlier after a Notepad++ update quietly strengthened its updater against hijacking. The episode underlines a broader vulnerability in the global software supply chain. Open-source tools such as Notepad++ are deeply embedded in corporate and government systems, yet are often maintained with limited resources. That imbalance makes them attractive targets for state-backed hackers seeking discreet access rather than noisy disruption.  Notepad++ developers have urged users to update manually to the latest version and large organisations to consider restricting automated updates. The incident also serves as a reminder that even modest, familiar software can become a conduit for serious espionage when its infrastructure is neglected.

China-linked group attacks ESET discovered both SpellBinder and WizardNet, tools used by Chinese hackers. A China-based APT group, “The Wizards,” has been linked to a lateral movement tool, Spellbinder, which allows adversary-in-the-middle (AitM) attacks.  It does so via IPv6 stateless address autoconfiguration (SLAAC) spoofing, to roam laterally in the compromised network, blocking packets and redirecting the traffic of legal Chinese software to download malicious updates from a server controlled by threat actors, ESET researchers said to The Hacker News.  About malware WizardNet The attack creates a path for a malicious downloader which is delivered by hacking the software update mechanism linked with Sogou Pinyin. Later, the downloader imitates a conduit to deploy a modular backdoor called WizardNet.  In the past, Chinese hackers have abused Sogou Pinyin’s software update process to install malware. Last year, ESET reported a hacking group called Blackwood that delivered an implant called NSPX30 by abusing the update process of the Chinese input method software app.  This year, the Slovak cybersecurity company found another threat actor called PlushDaemon that exploited the same process to deploy a custom downloader called LittleDaemon.  The scale of the attack The Wizards APT has targeted both individuals and the gambling industry in Hong Kong, Mainland China, Cambodia, the United Arab Emirates, and the Phillippines.  Findings highlight that the Spellbinder IPv6 AitM tool has been active since 2022. A successful attack is followed by the delivery of a ZIP archive which includes four separate files.  After this, the threat actors install “wincap.exe” and perform "AVGApplicationFrameHost.exe," to sideload the DLL. The DLL file then reads shellcode from “log.dat” and runs it in memory, resulting in the launch of Spellbinder.  Not the first time In a 2024 attack incident, the hackers utilized this technique to hack the software update process for Tencent QQ at the DNS level to help a trojanized version deploy WizardNet; a modular backdoor that can receive and run .NET payloads on the victim host. Spellbinder does this by blocking the DNS query for the software update domain ("update.browser.qq[.]com") and releasing a DNS response  “The list of targeted domains belongs to several popular Chinese platforms, such as Tencent, Baidu, Xunlei, Youku, iQIYI, Kingsoft, Mango TV, Funshion, Yuodao, Xiaomi and Xioami's Miui, PPLive, Meitu, Quihoo 360, and Baofeng,” reports The Hacker News.