11 ms·

This looks cool. I ran this on some web crawl data I have locally, so: all files you'd find on regular websites; HTML, CSS, JavaScript, fonts etc. It identifie

This looks cool. I ran this on some web crawl data I have locally, so: all files you'd find on regular websites; HTML, CSS, JavaScript, fonts etc. It identified some simple HTML files (html, head, title, body, p tags and not much else) as "MS Visual Basic source (VBA)", "ASP source (code)", and "Generic text document" where the `file` utility correctly identified all such examples as "HTML document text". Some woff and woff2 files it identified as "TrueType Font Data", others are "Unknown binary data (unknown)" with low confidence guesses ranging from FLAC audio to ISO 9660. Again, the `file` utility correctly identifies these files as "Web Open Font Format". I like the idea, but the current implementation can't be relied on IMO; especially not for automation. A minor pet peeve also: it doesn't seem to detect when its output is a pipe and strip the shell colour escapes resulting in `^[[1;37` and `^[[0;39m` wrapping every line if you pipe the output into a vim buffer or similar.

michaelmior 3y ago
> the current implementation can't be relied on IMO What's your reasoning for not relying on this? (It seems to me that this would be application-dependent at the very least.)
- jdiff 3y ago
  I'm not the person you asked, but I'm not sure I understand your question and I'd like to. It whiffed multiple common softballs, to the point it brings into question the claims made about its performance. What reasoning is there to trust it?
  - michaelmior 3y ago
    > It whiffed multiple common softballs I must have missed this in the article. Where was this?
    - deleted 3y ago
      [deleted]
    - jdiff 3y ago
      ...It's in the comment you were responding to. Directly above the section you quoted.
      - michaelmior 3y ago
        I understand that, but it wasn't clear to me where those examples came from.
        jdiff 3y ago
        It's pretty obvious from the whole comment that they're his own experience. Are you going anywhere with this or are you just saying things?
  - EnigmaFlare 3y ago
    It had 3 failures. How is that a sign it's untrustworthy? I'm sure all alternatives have more than 3 failures. You might be making assumptions about the distribution of successes and failures (GP didn't say how many files they tested to find those 3) or how "soft" they were. In an extreme case, they might even have been crafted adversarial examples. But even if not, they might have features that really do look more like some other file type from the point of view of the classifier even if it's not easily apparent to a human. Being strictly superior to a competent human is a pretty high bar to set.
    - epcoa 3y ago
      > or how "soft" they were. From the comment: It identified some simple HTML files (html, head, title, body, p tags and not much else) as "MS Visual Basic source (VBA)", "ASP source (code)", and "Generic text document" where the `file` utility correctly identified all such examples as "HTML document text". That's pretty soft. Nothing "adversarial" claimed either. > Being strictly superior to a competent human is a pretty high bar to set. The bar is the file utility.
      - EnigmaFlare 3y ago
        Those are only soft to a human. I looked at a couple and I picked them correctly but I don't know what details the classifier was seeing which I was blind to. Not to say it was correct, just that we can't call them soft just because they're short and easy for a human. > The bar is the file utility. It has higher accuracy than that. You would reject it just because the failures are different even though they're less?
        jdiff 3y ago
        Yes. Unpredictable failures are significantly worse than predictable ones. If file messes up, it's because it decided a ZIP-based document was a generic ZIP file. If Magika messes up, it's entirely random. I can work around file's failure modes, especially if it's one I work with often. Magika's failure modes strike at random and are not possible to anticipate. File also bails out when it doesn't know, a very common failure mode in Magika is that it confidently returns a random answer when it wasn't trained on a file type.
- TomNomNom 3y ago
  It provided the wrong file-types for some files, so I cannot rely on its output to be correct. If you wanted to, for example, use this tool to route different files to different format-specific handlers it would sometimes send files to the wrong handlers.
  - michaelmior 3y ago
    Except a 100% correct implementation doesn't exist AFAIK. So if I want to do anything that makes a decision based on the type of a file, I have to pick some algorithm to do that. If I can do that correctly 99% of the time, that's better than not being able to make that decision at all, which is where I'm left if a perfect implementation doesn't exist.
    - jdiff 3y ago
      Nobody's asking for perfection. But the AI is offering inexplicable and obvious nondeterministic mistakes that the traditional algorithms don't suffer from. Magika goes wrong and your fonts become audio files and nobody knows why. Magic goes wrong and your ZIP-based documents get mistaken for generic ZIP files. If you work with that edge case a lot, you can anticipate it with traditional algorithms. You can't anticipate nondeterministic hallucination.
      - jsnell 3y ago
        Where are you getting the non-determinism part from? It would seem surprising for there to be anything non-deterministic about an ML model like this, and nothing in the original reports seems to suggest that either.
        TeMPOraL 3y ago
        Large ML models tend to be uncorrectably non-deterministic simply from doing lots of floating point math in parallel. Addition and multiplication of floats is neither commutative nor associative - you may get different results depending on the order in which you add/multiply numbers.
ebursztein 3y ago
Thanks for the feedback -- we will look into it. If you can share with us the list of URL that would be very helpful so we can reproduce - send us an email at magika-dev@google.com if that is possible. For crawling we have planned a head only model to avoid fetching the whole file but it is not ready yet -- we weren't sure what use-cases would emerge so that is good to know that such model might be useful. We mostly use Magika internally to route files for AV scanning as we wrote in the blog post, so it is possible that despite our best effort to test Magika extensively on various file types it is not as good on fonts format as it should be. We will look into. Thanks again for sharing your experience with Magika this is very useful.
- TomNomNom 3y ago
  Sure thing :) Here's[0] a .tgz file with 3 files in it that are misidentified by magika but correctly identified by the `file` utility: asp.html, vba.html, unknown.woff These are files that were in one of my crawl datasets. [0]: https://poc.lol/files/magika-test.tgz https://poc.lol/files/magika-test.tgz
  - ebursztein 3y ago
    Thank you - we are adding them to our test suit for the next version.
    - TomNomNom 3y ago
      Super, thank you! I look forward to it :) I've worked on similar problems recently so I'm well aware of how difficult this is. An example I've given people is in automatically detecting base64-encoded data. It seems easy at first, but any four, eight, or twelve (etc) letter word is technically valid base64, so you need to decide if and how those things should be excluded.
  - beeboobaa 3y ago
    Do you have permission to redistribute these files?

michaelmior 3y ago

> the current implementation can't be relied on IMO What's your reasoning for not relying on this? (It seems to me that this would be application-dependent at the very least.)

jdiff 3y ago
I'm not the person you asked, but I'm not sure I understand your question and I'd like to. It whiffed multiple common softballs, to the point it brings into question the claims made about its performance. What reasoning is there to trust it?
- michaelmior 3y ago
  > It whiffed multiple common softballs I must have missed this in the article. Where was this?
  - deleted 3y ago
    [deleted]
  - jdiff 3y ago
    ...It's in the comment you were responding to. Directly above the section you quoted.
    - michaelmior 3y ago
      I understand that, but it wasn't clear to me where those examples came from.
      - jdiff 3y ago
        It's pretty obvious from the whole comment that they're his own experience. Are you going anywhere with this or are you just saying things?
- EnigmaFlare 3y ago
  It had 3 failures. How is that a sign it's untrustworthy? I'm sure all alternatives have more than 3 failures. You might be making assumptions about the distribution of successes and failures (GP didn't say how many files they tested to find those 3) or how "soft" they were. In an extreme case, they might even have been crafted adversarial examples. But even if not, they might have features that really do look more like some other file type from the point of view of the classifier even if it's not easily apparent to a human. Being strictly superior to a competent human is a pretty high bar to set.
  - epcoa 3y ago
    > or how "soft" they were. From the comment: It identified some simple HTML files (html, head, title, body, p tags and not much else) as "MS Visual Basic source (VBA)", "ASP source (code)", and "Generic text document" where the `file` utility correctly identified all such examples as "HTML document text". That's pretty soft. Nothing "adversarial" claimed either. > Being strictly superior to a competent human is a pretty high bar to set. The bar is the file utility.
    - EnigmaFlare 3y ago
      Those are only soft to a human. I looked at a couple and I picked them correctly but I don't know what details the classifier was seeing which I was blind to. Not to say it was correct, just that we can't call them soft just because they're short and easy for a human. > The bar is the file utility. It has higher accuracy than that. You would reject it just because the failures are different even though they're less?
      - jdiff 3y ago
        Yes. Unpredictable failures are significantly worse than predictable ones. If file messes up, it's because it decided a ZIP-based document was a generic ZIP file. If Magika messes up, it's entirely random. I can work around file's failure modes, especially if it's one I work with often. Magika's failure modes strike at random and are not possible to anticipate. File also bails out when it doesn't know, a very common failure mode in Magika is that it confidently returns a random answer when it wasn't trained on a file type.
TomNomNom 3y ago
It provided the wrong file-types for some files, so I cannot rely on its output to be correct. If you wanted to, for example, use this tool to route different files to different format-specific handlers it would sometimes send files to the wrong handlers.
- michaelmior 3y ago
  Except a 100% correct implementation doesn't exist AFAIK. So if I want to do anything that makes a decision based on the type of a file, I have to pick some algorithm to do that. If I can do that correctly 99% of the time, that's better than not being able to make that decision at all, which is where I'm left if a perfect implementation doesn't exist.
  - jdiff 3y ago
    Nobody's asking for perfection. But the AI is offering inexplicable and obvious nondeterministic mistakes that the traditional algorithms don't suffer from. Magika goes wrong and your fonts become audio files and nobody knows why. Magic goes wrong and your ZIP-based documents get mistaken for generic ZIP files. If you work with that edge case a lot, you can anticipate it with traditional algorithms. You can't anticipate nondeterministic hallucination.
    - jsnell 3y ago
      Where are you getting the non-determinism part from? It would seem surprising for there to be anything non-deterministic about an ML model like this, and nothing in the original reports seems to suggest that either.
      - TeMPOraL 3y ago
        Large ML models tend to be uncorrectably non-deterministic simply from doing lots of floating point math in parallel. Addition and multiplication of floats is neither commutative nor associative - you may get different results depending on the order in which you add/multiply numbers.

ebursztein 3y ago

Thanks for the feedback -- we will look into it. If you can share with us the list of URL that would be very helpful so we can reproduce - send us an email at magika-dev@google.com if that is possible. For crawling we have planned a head only model to avoid fetching the whole file but it is not ready yet -- we weren't sure what use-cases would emerge so that is good to know that such model might be useful. We mostly use Magika internally to route files for AV scanning as we wrote in the blog post, so it is possible that despite our best effort to test Magika extensively on various file types it is not as good on fonts format as it should be. We will look into. Thanks again for sharing your experience with Magika this is very useful.

TomNomNom 3y ago
Sure thing :) Here's[0] a .tgz file with 3 files in it that are misidentified by magika but correctly identified by the `file` utility: asp.html, vba.html, unknown.woff These are files that were in one of my crawl datasets. [0]: https://poc.lol/files/magika-test.tgz https://poc.lol/files/magika-test.tgz
- ebursztein 3y ago
  Thank you - we are adding them to our test suit for the next version.
  - TomNomNom 3y ago
    Super, thank you! I look forward to it :) I've worked on similar problems recently so I'm well aware of how difficult this is. An example I've given people is in automatically detecting base64-encoded data. It seems easy at first, but any four, eight, or twelve (etc) letter word is technically valid base64, so you need to decide if and how those things should be excluded.
- beeboobaa 3y ago
  Do you have permission to redistribute these files?