There are various entry types defined in IEEEtranS.bst that would fit such an entry, like booklet, techreport, unpublished, misc, electronic. The electronic entry seems to produce the format in your example.
Code (.bib file):
@IEEEtranBSTCTL{IEEEexample:BSTcontrol,
CTLdash_repeated_names = "no"
}
@booklet{dechauxbo,
author = {Jonathan Dechaux and Eric Filiol and Jean-Paul Fizaine},
title = {Office Documents: New Weapons of Cyberwarfare},
url = {http://archive.hack.lu/2010/Filiol-Office-Documents-New-Weapons-of-Cyberwarfare-paper.pdf},
organization = {ESIEA Laval, Laboratoire de cryptologie et de virologie op\'erationnelles},
address = {38 rue des Dr Calmette et Gu\'erin, 53000 Laval, France},
year = {2010}
}
@techreport{dechauxtr,
author = {Jonathan Dechaux and Eric Filiol and Jean-Paul Fizaine},
title = {Office Documents: New Weapons of Cyberwarfare},
url = {http://archive.hack.lu/2010/Filiol-Office-Documents-New-Weapons-of-Cyberwarfare-paper.pdf},
institution = {ESIEA Laval},
year = {2010}
}
@unpublished{dechauxup,
author = {Jonathan Dechaux and Eric Filiol and Jean-Paul Fizaine},
title = {Office Documents: New Weapons of Cyberwarfare},
url = {http://archive.hack.lu/2010/Filiol-Office-Documents-New-Weapons-of-Cyberwarfare-paper.pdf},
year = {2010}
}
@misc{dechauxmi,
author = {Jonathan Dechaux and Eric Filiol and Jean-Paul Fizaine},
title = {Office Documents: New Weapons of Cyberwarfare},
url = {http://archive.hack.lu/2010/Filiol-Office-Documents-New-Weapons-of-Cyberwarfare-paper.pdf},
organization = {ESIEA Laval},
year = {2010}
}
@electronic{dechauxel,
author = {Jonathan Dechaux and Eric Filiol and Jean-Paul Fizaine},
title = {Office Documents: New Weapons of Cyberwarfare},
url = {http://archive.hack.lu/2010/Filiol-Office-Documents-New-Weapons-of-Cyberwarfare-paper.pdf},
year = {2010}
}
Code (.tex):
\documentclass{IEEEtran}
\begin{document}
\bstctlcite{IEEEexample:BSTcontrol}
\noindent \cite{dechauxbo} booklet\\
\cite{dechauxtr} techreport\\
\cite{dechauxup} unpublished\\
\cite{dechauxmi} misc\\
\cite{dechauxel} electronic
\bibliographystyle{IEEEtranS}
\bibliography{dechaux}
\end{document}
Result:

Note that I have included the full organization and address only for the booklet entry, most other types also support these fields. The BSTcontrol part is just to print the author names on repeated entries for this example (see Is it normal for BibTeX to replace similar author names with "------"?), it is not needed in a real document (unless you want to suppress the dash of course).
IEEEtranbibliography style. Do you use a citation management package, such ascite? – Mico Apr 11 '19 at 09:16