[R-pkg-devel] Possible malware(?) in a vignette

[Bob Rudis]

The current one on CRAN does get flagged for some low-level Sigma rules b/c
of one of way a few URLs interact. I don't know if f-secure is
pedantic enough to call that malicious (it probably is, though). The
*current* PDF is "fine".

There is a major problem with the 2020 version. The file Iñaki's URL
matches the PDF that I grabbed from the Wayback Machine for the 2020 PDF
from that URL.

Simon's assertion about this *2020* file is flat out wrong. It's very bad.

Two VT sandboxes used Adobe Acrobat Reader to open the PDF and the PDF
seems to either had malicious JavaScript or had been crafted sufficiently
to caused a buffer overflow in Reader that then let it perform other
functions on those sandboxes.

They are most certainly *not* false positives, and dismissing that outright
is not great.

I'm not going to check every 2020 PDF from CRAN, but this is a big signal
to me there was an issue *somewhere* in that time period.

I do not know what cran.r-project.org resolved to for the Common Crawl at
that date (which is where archive.org picked it up to archive for the 2020
PDF version). I highly doubt the Common Crawl DNS resolution process was
spoofed _just for that PDF URL_, but it may have been for CRAN in general
or just "in general" during that crawl period.

It is also possible some malware hit CRAN during portions of that time
period and infected more than one PDF.

But, outright suggesting there is no issue was not the way to go, here.
And, someone should likely at least poke at more 2020 PDFs from CRAN
vignette builds (perhaps just the ones built that were JSS articles…it's
possible the header image sourced at that time was tampered with during
some time window, since image decoding issues have plagued Adobe Reader in
buffer overflow land for a long while).

- boB


On Thu, Jan 25, 2024 at 9:44 PM Simon Urbanek <simon.urbanek using r-project.org>
wrote:

> Iñaki,
>
> I think you got it backwards in your conclusions: CRAN has not generated
> that PDF file (and Windows machines are not even involved here), it is the
> contents of a contributed package, so CRAN itself is not compromised. Also
> it is far from clear that it is really a malware - in fact it's certainly
> NOT what the website you linked claims as those tags imply trojans
> disguising ZIPped executables as PDF, but the file is an actual valid PDF
> and not even remotely a ZIP file (in fact is it consistent with pdflatex
> output). I looked at the decompressed payload of the PDF and the only
> binary payload are embedded fonts so my guess would be that some byte
> sequence in the fonts gets detected as false-positive trojan, but since
> there is no detail on the report we can just guess. False-positives are a
> common problem and this would not be the first one. Further indication that
> it's a false-positive is that a simple re-packaging the streams (i.e. NOT
> changing the actual PDF contents) make the same file pass the tests as
> clean.
>
> Also note that there is a bit of a confusion as the currently released
> version (poweRlaw 0.80.0) does not get flagged, so it is only the archived
> version (from 2020).
>
> Cheers,
> Simon
>
>
>
> > On 26/01/2024, at 12:02 AM, Iñaki Ucar <iucar using fedoraproject.org> wrote:
> >
> > On Thu, 25 Jan 2024 at 10:13, Colin Gillespie <csgillespie using gmail.com>
> wrote:
> >>
> >> Hi All,
> >>
> >> I've had two emails from users in the last 24 hours about malware
> >> around one of my vignettes. A snippet from the last user is:
> >>
> >> ---
> >> I was trying to install a R package that depends on PowerRLaw two
> >> weeks ago.  However my virus protection software F secure did not
> >> allow me to install it from CRAN, while installation from GitHub
> >> worked normally. Virus protection software claimed that
> >> d_jss_paper.pdf is compromised. I asked about this from our IT support
> >> and they asked it from the company F secure. Now F secure has analysed
> >> the file and according them it is malware.
> >>
> >> “Upon analyzing, our analysis indicates that the file you submitted is
> >> malicious. Hence the verdict will remain
> >
> > See
> https://www.virustotal.com/gui/file/9486d99c1c1f2d1b06f0b6c5d27c54d4f6e39d69a91d7fad845f323b0ab88de9/behavior
> >
> > According to the sandboxed analysis, there's something there trying to
> > tamper with the Acrobat installation. It tries several Windows paths.
> > That's not good.
> >
> > The good news is that, if I recreate the vignette from your repo, the
> > file is different, different hash, and it's clean.
> >
> > The bad news is that... this means that CRAN may be compromised. I
> > urge CRAN maintainers to check all the PDF vignettes and scan the
> > Windows machines for viruses.
> >
> > Best,
> > Iñaki
> >
> >
> >>
> >> ---
> >>
> >> Other information is:
> >>
> >> * Package in question:
> >> https://cran.r-project.org/web/packages/poweRlaw/index.html
> >> * Package hasn't been updated for three years
> >> * Vignette in question:
> >>
> https://cran.r-project.org/web/packages/poweRlaw/vignettes/d_jss_paper.pdf
> >>
> >> CRAN asked me to fix
> >> https://cran.r-project.org/web/checks/check_results_poweRlaw.html a
> >> couple of days ago - which I'm in the process of doing.
> >>
> >> Any ideas?
> >>
> >> Thanks
> >> Colin
> >>
> >> ______________________________________________
> >> R-package-devel using r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-package-devel
> >
> >
> >
> > --
> > Iñaki Úcar
> >
>
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> R-package-devel using r-project.org mailing list
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>

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