Warsaw HackerspaceYou wouldn't NixOS a payphone
| Website | https://hannesweissteiner.com/ |
Hannes Weissteiner
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PhD Candidate at @isec_tugraz. Playing CTF with LosFuzzys
Ars TechnicaWebsites have a new way to spy on visitors: analyzing their SSD activity
Telltale SSD activity can be measured in the browser using simple JavaScript.
https://arstechnica.com/security/2026/05/websites-have-a-new-way-to-spy-on-visitors-analyzing-their-ssd-activity/?utm_brand=arstechnica&utm_social-type=owned&utm_source=mastodon&utm_medium=social
Announcing my latest first-author paper, accepted to #DIMVA2026:
❄️ FROST: Fingerprinting Remotely using OPFS-based SSD Timing.
While SSD contention-based side channels have been demonstrated from native code before, we bring them to the browser.
We use the Origin-Private File System (OPFS), which allows any website to use up to 10GB (Firefox), or 60% of total disk space (other browsers), from JavaScript, without any user interaction or special permissions.
We use a file larger than system RAM to measure SSD latencies, bypassing the page cache to guarantee disk access.
From the resulting traces, we can infer website visits (even across browsers!) and application startups.
While we did most of our evaluations on macOS, the underlying mechanisms are platform-agnostic.
This is a feature, not a bug!
Read the paper here: https://hannesweissteiner.com/publications/frost/
Thanks to Tobias Weiser, @wayna, @vmcall, Fabian Rauscher, Jonas Juffinger and @lavados for the collaboration!
Update: seems like enough people complained that they reverted that decision:
https://share.remarkable.com/l/3gFzgmf5J3QCuA
Great, for now. I'm definitely keeping the old extension version archived though.
By the way: The last update to the chrome extension was in 2023, so maintenance cannot be an argument for the feature removal.
If you happen to have the old extension version, everything still works. However, it is hard to find the old version online.
I really liked my reMarkable Paper Pro. It was so nice to send PDF files of papers to it with one click using the browser extension, to review or annotate them.
A few days ago, they decided to remove that feature entirely. No patch notes, no message - just a silent update of the extension. Even the support agents didn't know what was causing the issue at first.
The new extension now converts websites to EPUBs (without pictures) - OR you can pay for a subscription to get their custom format, which includes pictures.
I assume they realized that allowing people to upload websites as PDFs (with pictures!) would hurt their subscription sales.
Also, the new extension cannot send PDF files at all.
There is NO official communication from reMarkable about this, only a number of confused posts online and negative reviews on the Chrome Web Store. All of their communication is about their new device they just released.
So, if you are thinking of buying the new reMarkable device, be aware that they may just remove some of its features in the future to hide them behind a paywall when they need more money.
SNeelaI went to Big Sur, California nearly month ago and the images look stunning. No picture of mine can do this gorgeous landscape justice, just driving along the coast is a surreal experience.
📷 Minolta X-700
🎞️ Fujifilm ISO 400
All photos at: https://fotos.snee.la/big_sur
#California #filmisnotdead #bigsur #analogphotography #believeinfilm #landscapephotography #photography
RSo, I recently saw some quiet discussion about a paper where researchers reverse-engineered and disclosed some attacks against PhotoDNA, the very-super-duper-secret algorithm used by tech megacorps to scan for illegal images.
They didn't make any code public, and so... I did: https://github.com/ArcaneNibble/open-alleged-photodna
A _complete_ reverse-engineering and commented Python reimplementation of the algorithm from publicly-leaked binaries.
This means that studying the algorithm and any potential flaws is now much more accessible.
This took only about two days (once I knew that there even _was_ a leaked binary to compare against), which just goes to again show that security through obscurity never works.
🔁 encouraged
ISEC @ TU GrazOur PhD students, Carina Fiedler, Sudheendra Neela (@vmcall) and Hannes Weissteiner (@hweissi) attended the NDSS Symposium 2026 in San Diego, California, this week to present their papers!
Check them out 👇
Carina Fiedler: Memory Band-Aid: A Principled Rowhammer Defense-in-Depth
https://www.ndss-symposium.org/ndss-paper/memory-band-aid-a-principled-rowhammer-defense-in-depth/
Sudheendra Neela: Eviction Notice: Reviving and Advancing Page Cache Attacks
https://www.ndss-symposium.org/ndss-paper/eviction-notice-reviving-and-advancing-page-cache-attacks/
Hannes Weissteiner: Continuous User Behavior Monitoring using DNS Cache Timing Attacks
https://www.ndss-symposium.org/ndss-paper/continuous-user-behavior-monitoring-using-dns-cache-timing-attacks/
I'm looking forward to presenting my paper, "Continuous User Behavior Monitoring using DNS Cache Timing Attacks" at NDSS next week!
We mount an Evict+Reload-style attack on the local DNS cache, detecting recently accessed domains and evicting to continuously monitor new accesses.
Our attack works from native code, even across virtual machines and containers.
We also run the attack in the browser from a malicious website, using JavaScript or even scriptless HTML+CSS.
Most underlying primitives are OS-agnostic!
Read the paper here: https://hannesweissteiner.com/publications/dmt/
Thanks to Roland Czerny, @silent_bits, @notbobbytables , Johanna Ullrich and @lavados for the amazing collaboration!