On Mon, 16 Nov 2020 00:37:11 -0000 (UTC), Arlen Holder wrote:
> As always, if you have experience with MSI related tools,
> please add value so that others benefit from what you can impart.
What is the LOGIC one would use to choose a zip vs exe vs msi installer?
For the record, here's Paul's input in a thread where it was asked the
logical question of how to choose _which_ to download, when given choices:
a. zip (including portable, but not always portable)
b. exe (including portable, but not always portable)
c. msi (how can we tell what the heck is inside them?)
From Paul: Sep 20, 2020, 7:13:38 PM
<
https://groups.google.com/g/alt.comp.microsoft.windows/c/xKgKyvS0Fvs/m/pAuFFRazBgAJ>
The OS recognizes the .msi as requiring the Windows Installer service.
Mayayana knows more about that, how it works inside.
An EXE could have anything in it. In the case of an INNO installer,
the first stage is probably an unpacker into %temp%. It is there to
help prevent casual inspection, with a secondary purpose to
compress the data and reduce download costs.
The ZIP is usually an attempt to compress the data, where the
obfuscation stage is saved for the next layer inside. For example,
someone might discover that the ZIP layer saves two bytes, then the
EXE inside the ZIP prevents casual inspection.
The MSI was probably intended to prevent casual inspection too,
to a point. Sometimes these things are given anonymous names
inside, and there's some sort of map file inside which maps
them to real names for later.
I would say the MSI offers the greatest promise of inspect-ability,
whereas the others are just as likely to be hiding the inevitable.
Some installers can "sniff" their environment, and avoid completing
the installation process as a result. For example, one installer could
tell you were using Linux and WINE on it. It could sense it was
inside a VM. It would only complete all operations at Host level
in a pure Windows environment. Now, if you didn't have an unpacker
for that one, you might not be able to inspect it. What was weird
about that product (commercial), is the thing the guy was protecting
was broken, and hardly worth the effort he put into it. AKA, a
mental case. It's like having a bank vault filled with Fools Gold.
In some cases, the "tools" on Virustotal can't inspect them either.
But usually it's the lesser-lights items on Virustotal that
are the clueless ones. The mainstream ones are generally pretty
good at disassembly. The only exception is virus scanners that
crash on large enough tarballs. The free Kaspersky scanner
crashes on a Firefox tarball for example. I try to sort
tarballs and put them some place not normally receiving
on-demand scans, so that won't happen.
Paul
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What is the LOGIC one would use to choose a zip vs exe vs msi installer?