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Reverse Trendnet TS-S402 firmware
Start reversing Trendnet TS-S402 firmware device.
First, we need to download the firmware from the vendor webpage. I downloaded the 2015 version:
wget http://downloads.trendnet.com/TS-S402/firmware/FW_TS-S402(2.00.13).zip

Next, unzip the firmware file:
unzip FW_TS-S402\(2.00.13\).zip

Using file command we can get some information from the firmware binary files:
file REMOTE_PACKAGE_2_30.bin
file TS-S402_FW_2_00_13.bin

Or not
🤬

Let's using binwalk - our best friend
😎
binwalk TS-S402_FW_2_00_13.bin

We can observe a lot of LZMA data, however, we got an interesting gzip compressed file as well. From this point, we can use the -x option to ignore LZMA compression and extract only the gzip file. Something like this:
binwalk -ex lzma TS-S402_FW_2_00_13.bin
-e: extraction option
-x: ignore option

Accessing the _TS-S402-FW... folder, we can observe two files:

file 20
20: POSIX tar archive (GNU)
Ok, 20 file is another compressed file. Let's renaming it and unarchiving it.
mv 20 20.tar
tar -xvf 20.tar

Yeah dude, it was a strong journey!
😎
mkdir sqsh
sudo mount rootfs.armeb.squashfs ./sqsh/ -t squash fs -o loop
If you got an error, don't worry about that!

If we look at the hexadecimal, we can see the file format:
cat rootfs.armeb.squashfs | xxd | less

and
./sasquatch rootfs.armeb.squashfs
ls
Last modified 2yr ago