I did a standard new wallet installation. I dont know if means off or watch only wallet. I did already transactions in the past. I got seed and private key. I guess i did something unsafe, anayway i thought to be safe  with seed authetication e private key. What should i do to prevent another robbery next time? Use a different version? Setup?

Hi,


my btc were stolen with an anonymous transaction. How was possible? Electrum should be a offline secure wallet? The receiver address is visible. Can i retreive my btc? Moreover, in the future how can i trust every offline wallet? Should i use more safe installation while installing the software ?I donwloaded the electrum sofware from the official site.