With the advanced, utilities workflow component, From variable to file you can save the contents of a variable as a file. The parameters are:
Variable name
The name of the variable, that should be saved into a file.
Decode base64
If the data in the variable is stored as an encoded base64 data stream, then you can enable this to convert the base64 data stream into a binary data stream.
File path
The file into which the contents of the variable is to be copied to.