Re: [OT] Re: ATTACK TO MY SYSTEM

From: John Bradford
Date: Wed Sep 24 2003 - 02:45:14 EST


> > I'm running my own mailserver and it's hard not to accept it. I have
> > basically done checks in the from and to headers. If it appears as a virus,
> > i lockout the smtp sender. It's not permenant. When the virus stops, i
> > unblock every one.
>
> I've noticed that they *ALL* have their From:, To:, and Subject: written in
> uppercase. So it's really easy to filter them out depending on the tools used.
> If a mail header either matches ^FROM:, ^TO: or ^SUBJECT: then it has high
> chances to be a spam/virus. I checked all my recent mails and a few months
> back in LKML and did not found anything except spam/viruses which match this.
> At least, we should be lucky that these virus writers don't fully respect
> protocols...

What protocols are you referring to?

RFC 822, section 3.4.7, makes clear that case is _not_ significant for
these field names. RFC 2822 doesn't change this.

Just because no commonly used E-Mail application seems to generate
uppercase field names, how do you know something like a password
auto-responder script won't?

That may not be a concern for you, but please don't spread
mis-information to others.

John.
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