Base64

We can use the base64 command to encode and transfer files to a target machine during an engagement.

To encode a file, we can use the following command:

base64 FILE_NAME -w 0

Command breakdown:

• FILE_NAME - Specifies the file to encode.
• -w - Specifies how many lines to output.

An example will be:

base64 myfile -w 0

Once we get our string, we can use the following command to decode and save the string as a file:

echo 'base64_string_here' | base64 -d > FILE_NAME

Command breakdown:

• 'base64_string_here' - The base64 string from the encode command.
• -d - Specifies the decode option.
• > FILE_NAME - Specifies the file to save the output to.

An example will be:

echo 'U2VjcmV0IGJhc2U2NAo=' | base64 -d > secret_message.txt