Rating: 4.5

The file given seems to be an XML file used for some software. I searched on google " " to hopefully find the tool that uses the same XML scheme. From this, I find that this file is used by "Logisim" (http://www.cburch.com/logisim/index.html).

After downloading the tool and loading the given file (change file extension to all file to import the given file), we see a circuit board with 4 * 7 switch on the top and a single digit panel in the center. From the prompt, we can assume we need to turn on some of the switches in order make a number "4" display in the panel.

Now, we need to translate the switches to a message. Because ASCII uses 7 bits, we can assume that the message is in ASCII.

Binary: 0110001 0110000 1000111 1101001
Decimal: 31 30 47 69
ASCII: 1 0 G i

Flag: vsctf{10Gi}

Original writeup (https://github.com/kiyotaka-akaiwa/ctf-writeups/tree/main/vsCTF/2022/Lost_Assignment).