Notepad++ supply chain attack breakdown

(securelist.com)

169 points | by natebc 3 hours ago

12 comments

  • Soerensen 2 hours ago
    The WinGUp updater compromise is a textbook example of why update mechanisms are such high-value targets. Attackers get code execution on machines that specifically trust the update channel.

    What's concerning is the 6-month window. Supply chain attacks are difficult to detect because the malicious code runs with full user permissions from a "trusted" source. Most endpoint protection isn't designed to flag software from a legitimate publisher's update infrastructure.

    For organizations, this argues for staged rollouts and network monitoring for unexpected outbound connections from common applications. For individuals, package managers with cryptographic verification at least add another barrier - though obviously not bulletproof either.

  • ashishb 2 hours ago
    I am running a lot of tools inside sandbox now for exactly this reason. The damage is confined to the directory I'm running that tool in.

    There is no reason for a tool to implicitly access my mounted cloud drive directory and browser cookies data.

    • troad 2 hours ago
      MacOS has been getting a lot of flak recently for (correct) UI reasons, but I honestly feel like they're the closest to the money with granular app permissions.

      Linux people are very resistant to this, but the future is going to be sandboxed iOS style apps. Not because OS vendors want to control what apps do, but because users do. If the FOSS community continues to ignore proper security sandboxing and distribution of end user applications, then it will just end up entirely centralised in one of the big tech companies, as it already is on iOS and macOS by Apple.

      • black_knight 1 hour ago
        I think we could get a lot further if we implement proper capability based security. Meaning that the authority to perform actions follows the objects around. I think that is how we get powerful tools and freedom, but still address the security issues and actually achieve the principle of least privilege.

        For FreeBSD there is capsicum, but it seems a bit inflexible to me. Would love to see more experiments on Linux and the BSDs for this.

        • h4x0rr 1 hour ago
          Eli5, what is that supposed to mean?
          • kibwen 46 minutes ago
            The original model of computer security is "anything running on the machine can do and touch anything it wants to".

            A slightly more advanced model, which is the default for OSes today, is to have a notion of a "user", and then you grant certain permissions to a user. For example, for something like Unix, you have the read/write/execute permissions on files that differ for each user. The security mentioned above just involves defining more such permissions than were historically provided by Unix.

            But the holy grail of security models is called "capability-based security", which is above and beyond what any current popular OS provides. Rather than the current model which just involves talking about what a process can do (the verbs of the system), a capability involves taking about what a process can do an operation on (the nouns of the system). A "capability" is an unforgeable cryptographic token, managed by the OS itself (sort of like how a typical OS tracks file handles), which grants access to a certain object.

            Crucially, this then allows processes to delegate tasks to other processes in a secure way. Because tokens are cryptographically unforgeable, the only way that a process could have possibly gotten the permission to operate on a resource is if it were delegated that permission by some other process. And when delegating, processes can further lock down a capability, e.g. by turning it from read/write to read-only, or they can e.g. completely give up a capability and pass ownership to the other process, etc.

            https://en.wikipedia.org/wiki/Capability-based_security

      • ashishb 2 hours ago
        It also has persistent permissions.

        Think about it from a real world perspective.

        I knock on your door. You invite me to sit with you in your living room. I can't easily sneak into your bed room. Further, your temporary access ends as soon as you exit my house.

        The same should happen with apps.

        When I run 'notepad dir1/file1.txt', the package should not sneakily be able to access dir2. Further, as soon as I exit the process, the permission to access dir1 should end as well.

        • lifeisgood99 1 hour ago
          A better example would be requiring the mailman to obtain written permission to step on your property every day. Convenience trumps maximal security for most people.
          • ashishb 56 minutes ago
            I would configure mailman with permanent write access to the mailbox area

            That's what I with my sandbox right now

      • symaxian 2 hours ago
        Sand-boxing such as in Snap and Flatpak?
        • troad 2 hours ago
          Notoriously not actually secure, at least in the case of Flatpak. (Can't speak to Snap)

          Not sure how something can be called a sandbox without the actual box part. As Siri is to AI, Flatpak is to sandboxes.

          • FergusArgyll 1 hour ago
            Doesn't it use bwrap under the hood? what's wrong with that?
            • okanat 1 hour ago
              Many apps require unnecessarily broad permissions with Flatpak. Unlike Android and iOS apps they weren't designed for environments with limited permissions.
          • jacobgkau 2 hours ago
            The XDG portal standards being developed to provide permissions to apps (and allow users to manage them), including those installed via Flatpak, will continue to be useful if and when the sandboxing security of Flatpaks are improved. (In fact, having the frontend management part in place is kind of a prerequisite to really enforcing a lot of restrictions on apps, lest they just stop working suddenly.)
        • nextos 2 hours ago
          Snap and Flatpak do both sandboxing and package management.

          You can use the underlying sandboxing with bwrap. A good alternative is firejail. They are quite easy to use.

          I prefer to centralize package management to my distro, but I value their sandboxing efforts.

          Personally, I think it's time to take sandboxing seriously. Supply chain attacks keep happening. Defense is depth is the way.

      • jacobgkau 2 hours ago
        > getting a lot of slack recently

        I think you mean a lot of flak? Slack would kind of be the opposite.

        • troad 2 hours ago
          Haha, yes, corrected. Thank you. I have a habit of fusing unrelated expressions.
      • its_magic 2 hours ago
        I'm sure that will contribute to the illusion of security, but in reality the system is thoroughly backdoored on every level from the CPU on up, and everyone knows it.

        There is no such thing as computer security, in general, at this point in history.

        • ashishb 2 hours ago
          > but in reality the system is thoroughly backdoored on every level from the CPU on up, and everyone knows it.

          Indeed. Why lock your car door as anyone can unlock and steal it by learning lock-picking?

          • its_magic 1 hour ago
            Residents of San Francisco ask themselves that question all the time.
        • rectang 2 hours ago
          There's a subtlety that's missing here: if your threat model doesn't include the actors who can access those backdoors, then computer security isn't so bad these days.

          That subtlety is important because it explains how the backdoors have snuck in — most people feel safe because they are not targeted, so there's no hue and cry.

          • autoexec 1 hour ago
            The backdoors snuck in because literally everyone is being targeted. Few people ever see the impact of that themselves or understand the chain of events that brought those impacts about.
    • taftster 2 hours ago
      I almost feel like this should just be the default action for all applications. I don't need them to escape out of a defined root. It's almost like your documents and application are effectively locked together. You have to give permissions for an app to extra data from outside of the sandbox.

      Linux has this capability, of course. And it seems like MacOS prompts me a lot for "such and such application wants to access this or that". But I think it could be a lot more fine-grained, personally.

      • josephg 2 hours ago
        I've been arguing for this for years. There's no reason every random binary should have unfettered, invisible access to everything on my computer as if it were me.

        iOS and Android both implement these security policies correctly. Why can't desktop operating systems?

        • giobox 1 hour ago
          The short answer is tech debt. The major mobile OSes got to build a new third party software platform from day 0 in the late 2000s, one which focused on and enforced priorities around power consumption and application sandboxing from the getgo etc.

          The most popular desktop OSes have decades of pre-existing software and APIs to support and, like a lot of old software, the debt of choices made a long time ago that are now hard/expensive to put right.

          The major desktop OSes are to some degree moving in this direction now (note the ever increasing presence of security prompts when opening "things" on macOS etc etc), but absent a clean sheet approach abandoning all previous third party software like the mobile OSes got, this arguably can't happen easily over night.

        • marky1991 2 hours ago
          Mobile platforms are entirely useless to me for exactly this reason, individual islands that don't interact to make anything more generally useful. I would never use any os that worked like that, it's for toys and disposable software only imo.
          • josephg 1 hour ago
            Mobile platforms are far more secure than desktop computing software. I'd rather do internet banking on my phone than on my computer. You should too.

            We can make operating systems where the islands can interact. Its just needs to be opt in instead of opt out. A bad Notepad++ update shouldn't be able to invisibly read all of thunderbird's stored emails, or add backdoors to projects I'm working on or cryptolocker my documents. At least not without my say so.

            I get that permission prompts are annoying. There are some ways to do the UI aspect in a better way - like have the open file dialogue box automatically pass along permissions to the opened file. But these are the minority of cases. Most programs only need to access to their own stuff. Having an OS confirmation for the few applications that need to escape their island would be a much better default. Still allow all the software we use today, but block a great many of these attacks.

            • jofla_net 47 minutes ago
              Both are true, and both should be allowed to exist as they serve different purposes.

              Sound engineers don't use lossy formats such as MP3 when making edits in preproduction work, as its intended for end users and would degrade quality cumulatively. In the same way someone working on software shouldn't be required to use an end-user consumption system when they are at work.

              It would be unfortunate to see the nuance missed just because a system isn't 'new', it doesn't mean the system needs to be scrapped.

          • okanat 48 minutes ago
            There is a middle ground (maybe even closer to more limited OS design principles) exist. It is not just toys. Otherwise neither UWP on Windows nor Flatpaks or Firejail would exist nor systemd would implement containerization features.

            In such a scenario, you can launch your IDE from your application manager and then only give write access to specific folders for a project. The IDE's configuration files can also be stored in isolated directories. You can still access them with your file manager software or your terminal app which are "special" and need to be approved by you once (or for each update) as special. You may think "How do I even share my secrets like Git SSH keys?". Well that's why we need services like the SSH Agent or Freedesktop secret-storage-spec. Windows already has this btw as the secret vaults. They are there since at least Windows 7 maybe even Vista.

        • IcyWindows 1 hour ago
          Windows has had this for over a decade, but no one wants to put their application in a sandbox.
          • akdev1l 1 hour ago
            If a sandbox is optional then it is not really a good sandbox

            naturally even flatpak on Linux suffers from this as legacy software simply doesn’t have a concept of permission models and this cannot be bolted on after the fact

            • okanat 59 minutes ago
              The containers are literally the "bolting on". You need to give the illusion of the software is running under a full OS but you can actually mount the system directories as read-only.
  • indigodaddy 47 minutes ago
    So if one were theoretically infected right now, would a Malwarebytes scan indicate as such?
  • nightshift1 27 minutes ago
  • Someone1234 2 hours ago
    I'm out of the loop: How did they bypass Notepad++'s digital signatures? I just downloaded it to double-check, and the installer is signed with a valid code-signing certificate.
  • yodon 57 minutes ago
    Is there a "detect infection and clean it up" app from a reputable source yet (beyond the "version 8.8.8 is bad" designator)?
  • troad 2 hours ago
    It now seems to be best practice to simultaneously keep things updated (to avoid newly discovered vulnerabilities), but also not update them too much (to avoid supply chain attacks). Honestly not sure how I'm meant to action those at the same time.
    • Marsymars 1 hour ago
      The easiest way to action as a user seems like it would be to use local package managers that includes something like Dependabot's cooldown config. I'm not aware of any local package managers that do something like this?

      https://docs.github.com/en/code-security/reference/supply-ch...

    • gruez 1 hour ago
      You basically need to make a trade-off between 0days and supply chain attacks. Browsers, office suite, media players, archivers, and other programs that are connected to the internet and are handling complex file formats? Update regularly, or at least keep an eye out for CVEs. A text editor, or any other program that doesn't deal with risky data? You're probably fine with auto update turned off
    • _carbyau_ 1 hour ago
      I imagine that it depends on the use case.

      Using notepad++ (or whatever other program) in a manner that deals with internet content a lot - then updating is the thing.

      Using these tools in a trusted space (local files/network only) : then don't update unless it needs to be different to do what you want.

      For many people, something in between because new files/network-tech comes and goes from the internet. So, update occasionally...

      • gruez 1 hour ago
        >Using notepad++ (or whatever other program) in a manner that deals with internet content a lot - then updating is the thing.

        Disagree. It's hard to screw up a text editor so much that you have buffer overflows 10 years after it's released, so it's probably safe. It's not impossible, but based on a quick search (though incomplete because google is filled with articles describing this incident) it doesn't look like there were any vulnerabilities that could be exploited by arbitrary input files. The most was some dubious vulnerability around being able to plant plugins.

    • taftster 2 hours ago
      In the early days, updates quite often made systems less stable, by a demonstrable margin. My dad once turned off all updates on his Windows machine, with the ensuing peril that you can imagine.

      Sadly, it feels like Microsoft updates lately have trended back towards being unreliable and even user hostile. It's messed up if you update and can't boot your machine afterwards, but here we are. People are going to turn off automatic updates again.

    • TingPing 2 hours ago
      I feel like supply chain attacks are the much rarer situation than real world exploits but I don’t have numbers.
      • krater23 2 hours ago
        Supply chain attacks have impact on more systems, so it's more likely that your system is one of it. Opening a poisoned textfile that contains a exploit that attacks your text editor and fits exactly to your version is a rare event compared to automatically contacting a server to ask for a executable to execute without asking you.
    • GauntletWizard 2 hours ago
      Unless there's an announcement of a zero day, update a month after each new release. Keeps you on a recent version while giving security systems and researchers time to detect threats.
    • worksonmine 2 hours ago
      Debian stable. If you need something to be on the bleeding edge install it from backports or build from source. But keep most of your system boring and stable. It has worked fine for me for years.
      • krater23 2 hours ago
        As long as you do regulary updates of your debian stable, you are not secured against supply chain attacks.
        • worksonmine 1 hour ago
          I don't think you understand Debian. There's a new release every 2 years. A few months before every release there's the so called package freeze on the testing branch. The version the packages are on at that point that's the version they will have for the next stable release. Between releases the only updates are security updates.

          Do you mean I should worry about the fixed CVEs that are announced and fixed for every other distribution at the same time? Is that the supply-chain attack you're referring to?

  • Willish42 2 hours ago
    > cmd /c "whoami&&tasklist&&systeminfo&&netstat -ano" > a.txt

    Naive question, but isn't this relatively safe information to expose for this level of attack? I guess the idea is to find systems vulnerable to 0-day exploits and similar based on this info? Still, that seems like a lot of effort just to get this data.

    • gruez 1 hour ago
      >I guess the idea is to find systems vulnerable to 0-day exploits and similar based on this info?

      You don't need 0days when you already have RCE on an unsandboxed system.

    • thatfunkymunki 2 hours ago
      it's not "just to get that data", it's to confirm level of access, check for potential other exploiters or security software, identify the machine you have access to, identify what the machine has network connectivity to, etc. The attacker then maintains the c2 channel and can then perform their actual objective with the help of the data they have obtained.
  • Erlangen 1 hour ago
    > Notably, the first scan of this URL on the VirusTotal platform occurred in late September, by a user from Taiwan.

    Could this be the attacker? The scan happened before the hack was first exposed on the forum.

    • gruez 1 hour ago
      You would be a dumbass to do that, because virustotal allows security researchers to see submitted samples/urls. The last thing you want to do is to draw attention to your C&C server.
  • porise 2 hours ago
    I guess package managers win in the end. I got two emails from my IT department in the last year telling me to immediately update it.
  • tonymet 2 hours ago
    I noticed I had version 8.9 on Dec 28, 2025 and it seems clean according to

    https://arstechnica.com/security/2026/02/notepad-updater-was...

    I recommend removing notepad++ and installing via winget which installs the EXE directly without the winGUP updater service.

    Here's an AI summary explaining who is affected.

    Affected Versions: All versions of Notepad++ released prior to version 8.8.9 are considered potentially affected if an update was initiated during the compromise window.

    Compromise Window: Between June 2025 and December 2, 2025.

    Specific Risk: Users running older versions that utilized the WinGUp update tool were vulnerable to being redirected to malicious servers. These servers delivered trojanized installers containing a custom backdoor dubbed Chrysalis.

  • bluenose69 2 hours ago
    The article starts out by saying that Notepad++ "is a text editor popular among developers". Really?
    • TingPing 2 hours ago
      • da_chicken 1 hour ago
        This might be a better link: https://survey.stackoverflow.co/2025/technology#1-dev-id-es

        It's listed as the third most popular IDE after Visual Studio Code and Visual Studio by respondents to Stack Overflow's annual survey. Interestingly, it's higher among professionals than learners. Maybe that's because learners are going to be using some of those newer AI-adjacent editors, or because learners are less likely to be using Windows at all.

        I'm sure people will leap to the defense of their chosen text editor, like they always do. "Oh, they separated vim and Neovim! Those are basically the same! I can combine those, really, to get a better score!" But I think a better takeaway is that it's incredible that Notepad++, an open source application exclusive to Windows that has had, basically, a single developer over the course of 22 years, has managed to reach such a widespread audience. Especially when Scintilla's other related editors (SciTE, EditPlus) essentially don't rate.

        • bee_rider 35 minutes ago
          I think the argument you made for combining vim and neovim is pretty good actually. But it seems pretty unique to those two editors (well, throw vi in there if it ever shows up on the chart), so “worst” case notepad++ would be bumped down just one spot.
        • gruez 1 hour ago
          >Maybe that's because learners are going to be using some of those newer AI-adjacent editors, or because learners are less likely to be using Windows at all.

          You can use the 2022 (ie. pre-chatgpt) results for control for that. The results are basically the same.

          https://survey.stackoverflow.co/2022/#most-popular-technolog...

    • jamesfinlayson 13 minutes ago
      I don't do a whole lot of development with it but if I need to open a random code file then it's much better than plain old Notepad.
    • billforsternz 1 hour ago
      I enjoy coding something new up in Notepad++, without any annoying autocomplete and jank. I call it unplugged (acoustic?) mode. Jeepers Visual Studio these days starts autocompleting if and while for example and sometimes doesn't respect normal keystrokes because it expects me to complete these kind of interactions instead.
    • kotaKat 2 hours ago
      First three things I install on any machine - 7zip, Notepad++, alternate browser.
      • kbelder 1 hour ago
        Same, but additionally Irfanview. And once upon a time, Media Player Classic used to be on that list.

        This train of thought made me go find https://www.oldversion.com/. For a while, that was invaluable.

      • whynotmaybe 51 minutes ago
        Same, I use ninite for that.
      • LostMyWords 1 hour ago
        Yes, but I start with the browser. What are the Notepad++ alternatives on Linux and MacOS, for those times when I have to use them?
        • nosrepa 10 minutes ago
          Geany. Both npp and geany use the same editor component.
        • dizhn 1 hour ago
          I love a feature of notepad++ where when you have documents open and exit, it won't bother you with a save dialog and when you open it again the previous state will be there. I found that mousepad on linux can do this.

          For something functionality close I would look at Kate.

          • netsharc 1 hour ago
            I love and hate it at the same time, just like my browser tabs hoarding, it means I currently have 218 open documents on Notepad++ (and 96 browser tabs). I might not even need them anymore, but it's always "I'll look at them... later".
        • bigstrat2003 44 minutes ago
          Sublime Text. I think it's better than Notepad++ and is available for all computer platforms, not just Windows.
        • paffdragon 1 hour ago
          Sublime maybe?
        • GuinansEyebrows 1 hour ago
          vim :)
    • maxpert 2 hours ago
      LOL I guess the editors using Notepad++ downvoted you :P