With your requirement, please take a look at component：TalendHelpCenter:tSalesforceOutput which write data into a Salesforce DB.
The work flow should be: input-->tSalesforceOutput(Attachment object).
Feel free to let us know if it is Ok with you.
What we can do is to make sure that Talend will be your best choice!
Thank you for your reply. We tried using tsalesforce output but when we try to put the path of the file in the 'Body' field of attachment it gives us error. When we check in salesforce the datatype for Body field is Base64 but in talend we can see as String only.