this post was submitted on 20 Aug 2026
222 points (99.1% liked)

Technology

87550 readers
3092 users here now

This is a most excellent place for technology news and articles.

Our Rules

  1. Follow the lemmy.world rules.
  2. Only tech related news or articles.
  3. Be excellent to each other!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, this includes using AI responses and summaries. To ask if your bot can be added please contact a mod.
  9. Check for duplicates before posting, duplicates may be removed
  10. Accounts 7 days and younger will have their posts automatically removed.

Approved Bots

founded 3 years ago
MODERATORS
L3s@lemmy.world
enu@lemmy.world
technopagan@lemmy.world
L4s@lemmy.world
L3s@hackingne.ws
222
AliExpress runs silent WebAudio fingerprinting that breaks Bluetooth multipoint (blog.laserphile.com)
submitted 5 days ago* (last edited 5 days ago) by inari@piefed.zip to c/technology@lemmy.world
17 comments fedilink hide all child comments
you are viewing a single comment's thread
view the rest of the comments
[โ€“] riskable@programming.dev 9 points 5 days ago (7 children)

Honestly, this doesn't sound like spyware. More like absurd optimization. Here's why: Audio devices often go to sleep (to save battery) and can take a second or two to wake up. That's enough time that the end user will miss the first second or two of audio.

By keeping the audio outputting something (even if it's just silence), they can guarantee that their little (often hilariously terrible) product videos will play the way they expect (which is loud and startling, of course!).

This is just one of those stupid tricks that's bad for energy use but good for ignorant users who might complain that the first second of every AliExpress video is silent ๐Ÿคท

The reason why I believe this to be the case is because there's really nothing unique or interesting to be learned from an audio output loop that's literally sending zeros through itself. If you wanted to use that to fingerprint a user, you wouldn't need to keep it active. You could pass a single zero (silence) through and be done.

[โ€“] fubarx@lemmy.world 48 points 5 days ago* (last edited 5 days ago) (4 children)

The WebAudio test is not the only measurement in these scripts. Inspection of the bundles found code that queries or measures:

  • canvas rendering and toDataURL()
  • WebGL renderer information, extensions, and shader precision
  • audio oscillator and analyser output
  • screen and viewport dimensions
  • device pixel ratio
  • hardware concurrency and device memory
  • installed browser plugins
  • supported audio and video formats
  • WebRTC behaviour
  • browser performance timing
  • mouse, touch, focus, and scroll events
  • device motion and orientation
  • properties commonly associated with browser automation

There is also code for serialising and encrypting results, making requests to Alibaba telemetry services, and sending data with fetch() or sendBeacon().

Not sure you need all this to play audio.

[โ€“] riskable@programming.dev 7 points 5 days ago (3 children)

If it's part of a fingerprinting lib, then they just fucked it up. Because the fingerprinting can be done in one ~16ms window of time when the script runs and then you can break down the audio objects and pretend nothing happened.

[โ€“] festus@lemmy.ca 2 points 3 days ago

Also because browsers support OfflineAudioContext, which lets you do the same things but doesn't try to output to speakers.

load more comments (2 replies)
load more comments (2 replies)
load more comments (4 replies)