Weekly spam summary on November 18th, 2006

November 19, 2006

This week, we:

  • got 15,266 messages from 269 different IP addresses.
  • handled 22,009 sessions from 1,693 different IP addresses.
  • received 897,934 connections from at least 48,417 different IP addresses.
  • hit a highwater of 10 connections being checked at once.

Just like last time, that is not a typo (and nothing on the system was affected enough to make me notice it before now, when my scripts started spitting out information for this). Apart from the huge connection volume, things are pretty much the same as last week; ironically, the highwater is lower.

Day Connections different IPs
Sunday 27,857 +7,529
Monday 25,752 +6,652
Tuesday 32,064 +7,395
Wednesday 32,050 +7,526
Thursday 173,814 +7,585
Friday 312,437 +6,042
Saturday 293,960 +5,688

Kernel level packet filtering top ten:

Host/Mask           Packets   Bytes         12859    617K           7756    403K       6340    312K           6325    329K          5730    314K        5532    259K           4732    227K          4396    224K        4261    205K         3947    181K

Overall things are quieter than last week.

  • and return from last week.
  • and got blocked for repeated bad HELOs.
  • is listed in dul.dnsbl.sorbs.net, although its hostname and WHOIS information doesn't look like a dynamic IP address. My best theory is that SORBS just listed the large SBC Internet block that it's in.
  • was blocked for repeatedly trying to send us phish spam.
  • is an algx.net dynamic IP address.
  • is a Vietnamese IP address with no reverse DNS.

Connection time rejection stats:

  46168 total
  26202 dynamic IP
  15926 bad or no reverse DNS
   2374 class bl-cbl
    317 class bl-sdul
    285 class bl-dsbl
    206 class bl-njabl
     89 class bl-spews
     76 cuttingedgemedia.com
     40 class bl-sbl
     38 class bl-ordb

Good old Cutting Edge Media; apparently they never give up. But then, this is completely typical of spammers. That these numbers are not hugely larger than last week suggests that most of the connections were greylisted away.

Three of the top 30 most rejected IP addresses were rejected 100 times or more; the leader was an internal UofT machine, followed by (135 times) and (134 times). 16 of the top 30 are currently in the CBL and 4 are currently in bl.spamcop.net.

This week's Hotmail numbers:

  • 3 messages accepted, at least one of which was spam (I know because I got it).
  • 1 message rejected because it came from a non-Hotmail email address (in this case, a msn.com username).
  • 41 messages sent to our spamtraps.
  • 5 messages refused because their sender addresses had already hit our spamtraps.
  • no messages refused due to their origin IP address.

And the final numbers:

what # this week (distinct IPs) # last week (distinct IPs)
Bad HELOs 2008 175 1780 151
Bad bounces 470 374 482 416

This week's winning bounce target is tosi, with 11 hits, then a couple of old usernames. Plausible usernames (as opposed to the usual random jumbles) seem to be the popular thing this week.

(Next week's bad bounces numbers are probably going to jump some, because I changed how we track them a bit. Up until now, we've only been logging the first bad bounce in a given SMTP session, for reasons that don't fit in this margin; we're now logging all of them.)

Written on 19 November 2006.
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Last modified: Sun Nov 19 02:36:51 2006
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