RsaCtfTool-GUI Is Not Heavily Maintained
sudo git clone https://github.com/Hellsender01/RsaCtfTool-GUI.git
cd RsaCtfTool-GUI
sudo chmod +x setup.sh
sudo bash setup.sh
To test the working of RsaCtfTool-GUI, Open in RsaCtfTool(from file menu) and hit start attack. After finishing you should get the flag.