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Defeating Bacteria In Hot Water Systems With A Heat Exchanger

August 31, 2026 by 62 Comments

The average hot water is a relatively simple appliance to understand. It uses gas or electricity to dump energy into water in the form of heat, keeping it at a pleasant temperature for uses like bathing and cleaning. Basic mechanisms are in place to ensure the water stays at a relatively constant temperature, neither too hot where it could cause burns, nor too cold such that it wouldn’t be fit for purpose.

One of the problems, though, is that sometimes storing water at the desired temperature can create the perfect breeding ground for bacteria. However, a neat little trick developed by NIST could solve that problem rather elegantly.

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What’s Mu Metal?

August 31, 2026 by 22 Comments

If you tear into old TVs or recording equipment, you may see shields made from some exotic-looking metal. Old timers will tell you it’s called mu metal, and its purpose is to — sort of — shield things from magnetic fields. The qualification is important. Unlike a conductive RF shield, mu metal doesn’t really stop a magnetic field. Instead, it gives magnetic flux an easier path to follow around whatever you’re trying to protect.

What’s In The Metal?

Mu metal belongs to a family of soft magnetic nickel-iron alloys. A typical modern formulation is about 80% nickel and 15% iron, with molybdenum and a few other elements making up most of the remainder. What makes it useful is its extremely high magnetic permeability. Commercial material can have relative permeability around 100,000 or more, and some specialty alloys can reach even higher.

You can think about reluctance as the magnetic equivalent of resistance. Put a high-permeability shell around something sensitive, and magnetic flux would much rather travel through the shell than through the space inside it, just like current tends to take the path of least resistance.

This works particularly well for DC and low-frequency fields, exactly where your usual copper or aluminum EMI shield isn’t much help.

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This Week In Security: Android Malware, VOIP Hijack, Signal Contact Discovery, And TeamPCP Arrests

August 28, 2026 by 4 Comments

On GitHub, [AyaanB] details buying a cheap Android TV streaming device, looking for, and finding, baked-in malware.

Multiple warnings have been issued by the FBI and CISA regarding malware on media box Android devices. Many devices have been caught participating in botnets providing residential proxies, ad-click fraud, and DDOS services. [AyaanB] sets out to discover if a $30 set-top streaming box is pre-infected with malware, and extracting it – without ever letting the device talk to the Internet or access other devices on the local network.

Picking a device named in the advisories, [AyaanB] discovered that it was, indeed, preloaded with multiple app stores and applications that wouldn’t typically make sense on a set-top TV box. After identifying the serial port test pads and obtaining a low-voltage serial adapter, they were able to gain access to the bootloader and from there dump the contents of the MMC over TFTP.

With the entire filesystem accessible out-of-body, proving it was infected with malware at the factory becomes simple: the malware is signed as a system application, baked onto the system partition of the MMC, granted SELinux exceptions to mark it as a system binary with shell privileges, and has multiple launch scripts to make sure it is executed even if partially removed. With the malware identified, [AyaanB] continues to dig through to uncover the capabilities.

By installing hooks into the low-level Android process spawning system, the malware installs hooks into every application as it is launched: even if an application isn’t trojaned already, by the time it finishes executing, it’s definitely been subverted. The functions patched and the methods used match the Vo1d botnet, which is used for account takeovers, residential proxies, free “VPN” services, and other unfriendly behavior.

Further digging into the system showed hooks for ad-click fraud, where hidden browser windows are allowed to run unthrottled and display overlays are configured to obscure ads below where the user may click. Other included tools bid in real-time ad auctions, claiming to directly publish ads to the user which may or may not be visible. To cap it all off, a root level backdoor allows botnet operators to access the systems directly and install additional tools.

Be sure to check out [AyaanB]’s writeup for more details on exfiltration methods and other malware found on the devices. Continue reading “This Week In Security: Android Malware, VOIP Hijack, Signal Contact Discovery, And TeamPCP Arrests” →

Australia’s Nationwide Phone Outage Was An Embarrassing Failure

August 27, 2026 by 28 Comments

The phones! They were one of the basic utilities of the 20th century, and were just about as reliable as death and taxes. Even when then power grid went down, you still had a fair shot of getting a phone call through thanks to the reliability of the Plain Old Telephone Service.

Today, we eschew the simplicity of copper and mechanical switches for the supreme bandwidth and capability of high-speed cellular connectivity. With that, we accept that the additional complexity comes with a risk of complicated failures that bring everything tumbling down. Australia’s largest telecommunications provider found that out to its peril just a few short months ago.

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FLOSS Weekly Episode 879: Easy Like Butter

August 26, 2026 by No comments

This week Jonathan chats with Nathan Freitas of the Guardian Project! What is going on at the forefront of Open Source and privacy advocacy? Where are we on a true Tor browser on iOS? And what’s the ideal solution to the Android Lockdown issue? Watch to find out!

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Hackaday Europe 2026: PCBs With A Plot

August 26, 2026 by No comments

Printed circuit boards were developed first for function over form. They were a way to mount components and connect them in a stable, robust fashion, while taking into regard things like packaging and cooling requirements to enable a circuit to function. Circuit boards often end up looking cool in a techy kind of way, but their aesthetic is usually very much secondary to their actual purpose.

Katrin Dietzsch likes to use her PCBs a little differently, however. She designs boards that are intended to be a narrative tool for tabletop roleplaying, and came down to Hackaday Europe 2026 to walk us through the development of this very whimsical hardware.

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AI Book Scanning: Just What Is A Rare Book?

August 25, 2026 by 113 Comments

One of the stories of the last few weeks has been that AI companies have been scanning books in very large numbers in order to train their models with content guaranteed to have been written before 2002, and thus AI free. It’s caused some outrage, because of the size of the operation, and because the scanning process is destructive. In particular the phrase being bandied around is that these are rare books, and it’s this phraseology I find problematic. I think it’s time to unpack why that is the case.

It’s Not Book Burning, Folks

Before I worked for Hackaday I had a long career in and around the publishing industry, mostly on the electronic side, but from time to time crossing paths with my colleagues in the world of paper-based publishing. I understand the appeal of a good book, I’ve spend a lot of my life among bibliophiles, and let’s just say I own a few books myself. In particular I understand the symbolism of destroying books, bringing to mind as it does the actions of repressive regimes. I have stood in Bebelplatz in Berlin where the photo of Nazi student organisation members burning the library of Magnus Hirschfeld’s institute was taken in 1933, and if you know me, you’ll have an idea why that’s close to home. But for all that, what the AI companies are doing is not the same thing.

In this case they’re destroying the books for two reasons. Firstly, as I remember from a previous employer in the publishing world, it’s much easier to digitise a stack of papers than it is a bound book. Thus I’m pretty sure that’s one reason they remove the binding before digitising the pages. Then secondly, as I understand it it’s a copyright issue. If they buy a book, digitise it, and destroy the physical copy, they can legitimately claim that only one copy of it exists, and they hope, sidestep copyright claims from publishers. Continue reading “AI Book Scanning: Just What Is A Rare Book?” →