Weekly spam summary on April 7th, 2007

April 8, 2007

This week, we:

  • got 13,022 messages from 240 different IP addresses.
  • handled 18,021 sessions from 1,234 different IP addresses.
  • received 169,572 connections from at least 5,382 different IP addresses.
  • hit a highwater of 43 connections being checked at once.

Volume is about the same as last week, although evidently we got a big burst of connections some time this week.

Day Connections different IPs
Sunday 25,317 +8,613
Monday 22,832 +7,879
Tuesday 26,190 +7,763
Wednesday 26,237 +7,283
Thursday 31,179 +9,209
Friday 21,908 +7,302
Saturday 15,909 +5,333

This is surprisingly flat, with the exception of Thursday; I'm used to more day to day fluctuations.

Kernel level packet filtering top ten:

Host/Mask           Packets   Bytes       26291   1277K cox.net       18222    885K cox.net       14045    637K bellsouth.net        13151    631K adelphia.net         10280    617K centrum.cz          10174    529K           9019    433K           8135    447K           4854    233K           3966    254K

This is about the same as last week, although this week all of the top five spots were claimed by advance fee fraud spam webmail senders; as with last week, I put them in the kernel level blocks early on.

  • and return from last week. I note with interest that is now in SBL53250, attributed to a 'Mesa Media'; I always like having my suspicions confirmed about blocks.
  •,, and are all part of 'webmaillogin.com', which we no longer accept email from after it sent us advance fee fraud spam (just like pretty much every other free webmail provider out there).

This is a rather depressing set of top ten IP addresses, and I think it illustrates the degree to which advance fee fraud spam has risen to be a serious problem.

Connection time rejection stats:

  45752 total
  24453 dynamic IP
  15061 bad or no reverse DNS
   4610 class bl-cbl
    261 class bl-pbl
    182 class bl-dsbl
    131 class bl-njabl
     82 cuttingedgemedia.com
     73 class bl-sdul
     69 reliablehosting.com
     64 midtowndeals.com
     54 acceleratebiz.com
     50 class bl-sbl

The highest SBL source this week was SBL52928 with 14 rejections (a hijacked server used to send spam), then SBL51080 with 8 rejections (a phish source).

Fourteen of the top 30 most rejected IP addresses were rejected 100 times or more this week; the leader was (216 times, a rr.com cablemodem). Seven of the top 30 are currently in the CBL, only two are currently in bl.spamcop.net, 8 are in the PBL, and a grand total of 15 are in zen.spamhaus.org.

(Locally, 15 were rejected as 'dynamic IP', 11 were rejected for bad or missing reverse DNS, one was a cuttingedgemedia.com machine, one was a reliablehosting.com machine, and there was a smattering of other reasons.)

This week, Hotmail managed:

  • 1 message accepted, probably not spam (but then, it wasn't from Hotmail itself).
  • 1 message rejected because it came from a non-Hotmail email address (a msn.com one, in this case).
  • 33 messages sent to our spamtraps.
  • no messages refused because their sender addresses had already hit our spamtraps.
  • 6 messages refused due to their origin IP address (three in the CBL, one from SBL38278, a listing from February 22nd 2006, one from Nigeria, and one from saix.net).

And the final numbers:

what # this week (distinct IPs) # last week (distinct IPs)
Bad HELOs 801 143 714 83
Bad bounces 27 20 37 22

The most active source of bad HELOs was (70 rejections), followed by (56 rejections). The bad HELO numbers are up compared to last week, but not hugely.

Bad bounces were sent to 25 different bad usernames this week; the most popular destinations at two attempts each were noreply and the made up username bridgetteswanson. About half the total bounces went to usernames like ShannonMueller, followed by a number of previously existing local usernames, and finally a few things like sandychampion.

Earthlink.net was the largest source of bad bounces, sending to both sorts of the firstname plus lastname bad usernames. The remaining bad bounces came from all over, with no particular pattern.

(I am sort of puzzled that we didn't get more bad bounces. While the spammers are clearly forging our domain on MAIL FROM addresses, they apparently aren't doing it on very much of their spam.)

Written on 08 April 2007.
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Last modified: Sun Apr 8 00:07:25 2007
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