[H-GEN] Software for sending bulk-email (need to throughput-test anti-spam filter)

Mark Suter suter at zwitterion.humbug.org.au
Tue Feb 10 08:29:26 EST 2004


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 2004-02-08, Christopher Biggs wrote:

> I did write a perl script, using libnet's Net::SMTP module.
> Naive approaches tend to be limited by the TCP handshake delay,
> and the TCP round-trip delay imposed by non-pipelined SMTP.

Let me tell you of an evil spammer trick that gets around this
pesky design feature of TCP.

    One thread sends out SYN packets to the victim mailservers.
    The "custom TCP stack" (just lowlevel libnet stuff) doesn't
    keep and record of the packets.

    One thread responds to any SYN-ACK packets with a ACK-FIN
    packet containing the entire spam.  Again, no records...

Evil!

Yours sincerely,

- -- Mark John Suter  | I know that you  believe  you understand
suter at humbug.org.au | what you think I said, but I am not sure
gpg key id 2C71D63D | you realise that what you  heard  is not
mobile 0411 262 316 | what I meant.        Robert J. McCloskey
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)
Comment: Check Keyservers or http://zwitterion.org/keys/

iD8DBQFAKNy2RYso2ixx1j0RAoZIAJ0ZsY23hN3MqrIxfNfuHVyHpMV6awCdG2t2
03x7MK26tT/nzufnmIrY/Hk=
=BK9Y
-----END PGP SIGNATURE-----




More information about the General mailing list