SQL & PL/SQL

I want to download the latest update of Symantec Antivirus daily. For that I use Ftp. The steps which I followed is as under

1) CREATE OR REPLACE DIRECTORY "my_docs" AS 'E:\Vrupdate\' ;

2) -- Retrieve a binary file from a remote FTP server.

DECLARE
l_conn UTL_TCP.connection;
BEGIN
l_conn := ftp.login('ftp.symantec.com', '21', 'guest','guest');
ftp.binary(p_conn => l_conn);
ftp.get(p_conn => l_conn,
p_from_file => '/AVDEFS/symantec_antivirus_corp/20081027-003-x86.exe',
p_to_dir => 'MY_DOCS',
p_to_file => 'update.exe');
ftp.logout(l_conn);
utl_tcp.close_all_connections;
END;

But it gives me error which is mention below

220 spftp/1.0.0000 Server [64.86.106.103]
331 Password required for USER.
230-
230- ---------------------------------------------------------------------------
230- WARNING: This is a restricted access system. If you do not have explicit
230- permission to access this system, please disconnect immediately!
230 ----------------------------------------------------------------------------
200 TYPE set to I.
227 Entering Passive Mode. (64,86,106,103,232,1)
150 Opening BINARY mode data connection for /AVDEFS/symantec_antivirus_corp/20081027-003-x86.exe (37113664 bytes).
226 Transfer Complete
ORA-29281: invalid MODE
ORA-06512: at "OAS.FTP", line 358
ORA-06512: at "OAS.FTP", line 451
ORA-06512: at line 7

Please Advice.

Regards