claro stub es lo que se encargar de descifrar y de ejecutar el archivo binario que ha sido cifrado por el crypter, ya que no se puede ejecutar si se encuentra cifrado.
pero por eso es necesario adjuntar las 2 cosas en 1, el stub y el binario cifrado y formar 1 ejecutable resultante.
Scantime: those type of crypters make your malware undetectable from antivirus software while your malware is not executed. It makes static analysis of your binary difficult because the malicious part of your malwares binary is encrypted. When the malware is executed the Stub decrypts the malicious part of the binary and it is loaded to memory. When it is in the memory in a decrypted form it is detectable by antivirus software.
Runtime: Scantime + only parts that are needed to execute a specific task are decrypted during runtime. After they finish their task the Stub encrypts them again.
el cripter de archivos en disco es ese scantime crypter , gracias por la info