Comments on: Spammy weather http://bit-player.org/2009/spammy-weather An amateur's outlook on computation and mathematics. Thu, 17 May 2012 09:59:47 +0000 http://wordpress.org/?v=2.6.3 By: Derek O'Connor http://bit-player.org/2009/spammy-weather#comment-2208 Derek O'Connor Mon, 31 Aug 2009 10:01:35 +0000 http://bit-player.org/?p=429#comment-2208 Read section 21.2.2.4 of Ross Anderson's book, Security Engineering, 2nd Ed., Wiley, 2008, where he talks about the 'lumpiness' of spam statistics. He says that most spam comes from several dozen large gangs. Anderson's website is worth a visit : http://www.cl.cam.ac.uk/~rja14/ Read section 21.2.2.4 of Ross Anderson’s book, Security Engineering, 2nd Ed., Wiley, 2008, where he talks about the ‘lumpiness’ of spam statistics. He says that most spam comes from several dozen large gangs.

Anderson’s website is worth a visit :

http://www.cl.cam.ac.uk/~rja14/

]]> By: Seo Services http://bit-player.org/2009/spammy-weather#comment-2207 Seo Services Thu, 27 Aug 2009 05:52:37 +0000 http://bit-player.org/?p=429#comment-2207 To compute the probability that the message is spam, taking into consideration all of its words or a relevant subset of them.I am satisfied by your way of research. To compute the probability that the message is spam, taking into consideration all of its words or a relevant subset of them.I am satisfied by your way of research.

]]> By: Ranjit http://bit-player.org/2009/spammy-weather#comment-2202 Ranjit Sat, 15 Aug 2009 04:15:43 +0000 http://bit-player.org/?p=429#comment-2202 Another (improbable) factor might be that spammers (or their funding corp.) are aware of (the constantly updated) GMail (or Yahoo etc) spam filters and they have dumped older strategies (explaining the fall) or come up with newer (higher success probability) strategies (explaining the rise). Again, very unlikely :) ... but then you never know how much research is going on in another area!! Another (improbable) factor might be that spammers (or their funding corp.) are aware of (the constantly updated) GMail (or Yahoo etc) spam filters and they have dumped older strategies (explaining the fall) or come up with newer (higher success probability) strategies (explaining the rise).

Again, very unlikely :) … but then you never know how much research is going on in another area!!

]]> By: Arvind Narayanan http://bit-player.org/2009/spammy-weather#comment-2201 Arvind Narayanan Fri, 14 Aug 2009 21:47:24 +0000 http://bit-player.org/?p=429#comment-2201 There was a very well publicized event <a href="http://www.google.com/search?q=McColo+Corp" rel="nofollow">last November when McColo Corp. was shut down</a> and spam volume dropped 75% before recovering. (It was around mid-Nov, which is why the month-to-month drop in your graph is less than 75%, and also why you see another dip in Dec even though traffic had started recovering by then.) There is a bottleneck not in terms of people but hosting companies doing the spamming. This is also the reason why the language ratios are stable -- the spammers and their hosts are probably uncorrelated in terms of geographic location. Apparently this kind of event happens once every couple of years, but everyone migrates to a different host and all is well in the spam world again. There was a very well publicized event last November when McColo Corp. was shut down and spam volume dropped 75% before recovering. (It was around mid-Nov, which is why the month-to-month drop in your graph is less than 75%, and also why you see another dip in Dec even though traffic had started recovering by then.) There is a bottleneck not in terms of people but hosting companies doing the spamming. This is also the reason why the language ratios are stable — the spammers and their hosts are probably uncorrelated in terms of geographic location. Apparently this kind of event happens once every couple of years, but everyone migrates to a different host and all is well in the spam world again.

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