nanog mailing list archives

Re: SPAM and Virus emails to NANOG


From: Valdis.Kletnieks () vt edu
Date: Fri, 19 Mar 2004 17:22:01 -0500

On Fri, 19 Mar 2004 17:10:21 EST, Jared Mauch said:

      These spoofed virii/worm/whatnot emails can be
somewhat prevented in a few cases by the utilization of SPF

Note that this isn't a totally foolproof method.  We have a large (50K+)
subscriber list that's flagged as "post by list manager only" - and one of the
address-scraping worms managed to get the list name into the To: and the
manager's name into the From:.  Multiple times.  Like 50+. (Overlooking the
multiple hundreds that got trapped because they managed to get the  list in the
To: but address scraped a From: that wasn't allowed through).

Of course, locality-of-reference being what it is, the (un)lucky machine
happened to be actually at our site, so SPF wouldn't have done anything to stop
it.  Remember that if foo.com is a large corporation (as opposed to an open
ISP), most address scrapers will get luckiest at getting 'foo.com' into both
the From: and To: headers if they manage to whack a machine that's actually a
legitimate foo.com box.

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