paulfr
I'm not 100% sure why some people thought it was a malicious file, but the comments on Virustotal mention [1] which, for me, redirects to the legitimate [2] but a comment seems to link it with [3] which is a completely different file. Perhaps the redirection is randomized so people got confused?
[1] hxxp://files.dodo-number-1.pw/p/MCLkP8Dzc3nUWJrG9fwGLA,1442015273/zte%20mf631%20firmware%20downlo_10924_i57945825_il345.exe (replace hxxp with http)
[2] https://download-installer.cdn.mozilla.net/pub/firefox/relea...
[3] https://www.virustotal.com/es/file/e6821e86a9d3fb693b32077e6...
Here the attacker just needs to patch a binary once and he already has complete control over the machine, so he has an infinite number of options: from simply manually replacing the binary file before it's uploaded to the website, to replacing gcc with a script that patches the source code before calling the original gcc.
The latter is supported by the fact that changelog entries don't discriminate between security bugs and normal bugs, and by the fact that no vulnerability was ever reported by the developers themselves.
More worryingly, in all instances where a vulnerability was reported, the CVE vulnerability was filed specifically because the reporters were security researchers. This means that when a normal user reported a crash bug, no vulnerability was EVER filed. How likely do you think it is that none of those crashes could possibly be turned into an exploit? There are 95 instances of "Some bugs were fixed" in the changelog.
7-zip is a widely popular basic utility, like a web browser. A flaw in 7-zip is very serious, because as I pointed out elsewhere simply opening a .zip file will allow an attacker to exploit it. And while there is a strong security culture among web browser developers, 7-zip doesn't seem to have that culture (yet).
There is certainly a massive budget and manpower difference, but a lack of mention of security fixes in the changelog and a lack of hashes isn't a manpower issue, it's a culture issue.
As a side note, compromise of a developer's machine is a big deal in my opinion: it could be easy for a criminal entity to slip in a tiny change in a large patch that introduces a vulnerability; and depending on how builds are performed, a criminal could patch the final .exe with no visible change to the source code. These are tailored attacks, but for a very widely distributed program it would easily be worth the criminal's time.
So simply opening a malicious ".zip" file on Windows could trigger the HFS+ vulnerability. Using 7-zip to open any file means you have a HUGE attack surface.
EDIT: One simple way to mitigate this issue would be to just throw a confirmation prompt if the file extension matches a known format but 7-zip is about to run a decoder for a different format.
The changelog only says "Some bugs were fixed", with no mention that there are serious security flaws. The homepage doesn't mention any vulnerability.
The installer is not signed, downloads are over HTTP only, and there is no hash available neither on the homepage or on the forum announcement linked from the homepage (the latter is served over HTTPS so it would be a reasonable option); thankfully you can dig around Sourceforge downloads to find a SHA-1 automatically generated by Sourceforge. So I can personally verify the integrity of downloads, assuming Sourceforge can still be trusted, but 99% of users won't do this, and more worryingly it's a strong signal that the developers may not understand or value security very much: you have to wonder if maybe they're not themselves downloading unsigned software over HTTP all the time.
Other pages on the translation blog follow the same pattern: an old webpage (this HN entry is from 2009, but other pages go back to 2000) is edited years later to link back to a bad translation in some random language.
This is very far from my area of expertise, so I'm curious to know if this is well-known, and if those pages were hacked or if this was inserted by the owner himself.
EDIT: This is fascinating. I'm finding dozens of similar blogs, with links spanning at least a thousand hosts, which I'm assuming were hacked. This is a big network, with sophisticated wording designed to look as innocent as possible.
I just downloaded the dataset, and color is such a powerful feature that training a random forest on images downsampled to a single pixel results in 95% and 98% accuracies! (for the 4-category and 6-category versions, respectively)
And you can easily exceed 99.5% by adding more features to the forest, which is far above their DBN accuracy.
I have no idea how they were able to get an accuracy as low as 69% when they evaluated random forests.
[1] https://team.inria.fr/alf/members/andre-seznec/defying-amdah...
You seem to be blissfully unaware that they're in fact the same researchers: André Seznec is a co-author of the paper.
This paper is valuable in pointing out that ITTAGE branch prediction performance is a very good predictor of Haswell performance. Because the Haswell algorithm is secret, that should be very helpful to developers who still have to care about branch prediction.
Interpreter developers shouldn't ignore pre-Haswell chips just yet, but if you were to, say, develop a new language your design decisions should be guided by where the puck will be rather than where it used to be.
The theorem seems entirely correct to me. You can prove it with these sub-steps:
(1) the set of all j + a_j is the set of nonnegative integers minus a finite number of gaps
(2) thus for large enough n you can express \sum_{j=1}^n (j + a_j) as a quadratic function of n, plus a residual term e(n) of magnitude at most 1007^2/2
(3) more precisely, \sum_{j=m+1}^n a_j = g (n-m) + e(n) - e(m) where g is the number of gaps in (1)
Then choosing b = g solves the problem.
Hope that helps.
I could control for demographic factors, but not for other major important factors in a child's development -- parental IQ or views regarding parenting are huge factors in a child's IQ, and they may also influence the decision of whether or not to breastfeed. If parenting books unanimously decided that formula was bad, then parents who cared enough about their children to read them and follow their advice would be more likely to breastfeed and you would see a positive correlation with IQ, even if formula was completely equivalent to breastfeeding.
So while there is a clear correlation after controlling for demographic, there is not necessarily a causation. My formulation really wasn't meant to imply causation, but rather the handling of unknown data (I grouped unknown-status children together with breastfed children). When talking about correlation, it's not meaningful to make a distinction between IQ impairment and IQ gain.
http://community.topcoder.com/longcontest/?module=ViewProble...
If they accept I'll have an opportunity to look deeper -- it's one thing to develop an efficient model, but fully exploiting it in order to gain a better understanding of the data takes some work. A limitation of these contests is that you're rewarded for producing a very efficient model, but there is very little emphasis on analysis of your model once you built it. I think it's a shame, because the person who built the model is often in the best position to have a good intuition of both the dataset and why the model had to be built that way.
I've been considering opening a blog, but I haven't found time to do so yet.
Briefly, the purpose of the contest wasn't to understand the effect of breastfeeding, but to understand how important normal child growth is to mental development. They included several scenarios: with all data available, with demographic data removed, and with demographic data and growth curves removed. Unfortunately, IQ is so overwhemingly affected by demographic that the scenarios without demographic data devolved into a game of extracting all the demographic data that was leaked by non-demographic variables. And when demographic data is available, more than 90% of the variance extracted by the model comes from demographic data rather than biological measurements!
It's really disheartening to think that depending on the social setting you come from, you start with an IQ of 85 or 115 -- at age 7...
I compared my dataset and their data, and it turns out that even in Brazil there is significant correlation between mother education and breastfeeding, barely less so than on the dataset I have. So you should probably disregard my edit in the above post: accounting for confounders could be important in both cases.
After reading the article I did some very quick computations and my finding based on the model I developed is that children who were not breastfed have an IQ impairment in the 1-3 IQ points range, after accounting for confounding factors.
This is very consistent with the results published here.
Compared to this study, I believe the methodology I'm using is more powerful for three reasons:
- much larger sample size: the dataset I have access to comprises 12015 children, compared to 3493 for the study
- a larger set of confounding factors is accounted for: notably, the data includes height and weight measurements at up to five points in time
- confounding factors are fully accounted for, rather than hand-waved away. This is a complex model based on random forests and linear model, and the results are entirely cross-validated.
Stay tuned for more detailed computations. I will also ask the organizers for the exact definition of breastfeeding used.
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Edit:
On the other hand, the study is still very appealing because according to the authors, there is little correlation between demographics and breastfeeding in Brazil, whereas the validity of the effect I'm reporting is dependent on whether the demographic model is powerful enough to remove the correlation. Still, I believe most of the correlation is easy to remove, and it isn't clear that there aren't subtle demographic effects even in Brazil. In particular, the proportion of participants with missing IQ data seems to decrease with duration of breastfeeding, and I don't know if they have an explanation for that.