How to Identify Installer Type and Extract It without Installing, Part 1: 7-Zip Prowess and NSIS Installer
7-Zip for All...! We can easily extract many installer types with this "little tool that can" do so much :) Even other archiver based on it like Bandizip can't do all of 7-Zip can.
And its "Open archive" prowess is so useful in identifying what kind of installer an executable is. We will see this prowess later in analyzing each installer type. The basic rule is to try to open any installer executable with 7-Zip first.
NSIS Installer
A good open source installer package that's very friendly with 7-Zip comes from our good old portable application developer's buddy: NSIS/Nullsoft Scriptable Install System.We will show you an example in which we have the chance to use some of 7-Zip neatest feature on the WPS Office installer executable. Let's open this archive,
As we can see here, there's a $PLUGINSDIR folder. This is the most typical property of an NSIS installer.
A glance at the "Packed Size" column, it's obvious that it stores most of its files in $_11_ folder, so let's go inside. There we find the main installer file called the $EXEFILE,
Let's right-click on it and select Open Inside,
Here we find a CONTROL folder without anything meaningful inside it. After all, its total size is only about 0.7MB,
Let's move up again to $EXEFILE but now let's try Open Inside * (with asterisk),
We got something big called [0]. If we select Open Inside on [0] it will open that CONTROL folder again—same thing with Open Inside *.
So let's now try that Open Inside # (with hash/fence), and it brings up something that 7-zip can recognize!
Now let's open the biggest archive called 4.7z with Open Inside and we finally find what we're looking for,
By the way, we can save time by opening the $EXEFILE with Open Inside # directly and find that 4.7z and the "bonanza" inside,
That's why we really love 7-Zip!
