Wandering Thoughts archives

Weekly spam summary on May 20th, 2006

This week we:

• got 12,292 messages from 221 different IP addresses.
• handled 16,875 sessions from 807 different IP addresses.
• received 125,999 connections from at least 41,642 different IP addresses.
• hit a highwater of 11 connections being checked at once.

Nothing went wrong this week, thank goodness; no reboots, no SMTP frontend restarts, nothing. Weekly volume seems to be back to the normal level when things are quiet; there's no sign of last week's Sunday spike. The per-day statistics are sufficiently boring and flat (peaking at 20,000 connections on Wednesday) that I'm not going to put them in.

Kernel level packet filtering top ten:

Host/Mask           Packets   Bytes
218.254.83.47         11876    570K
67.42.71.124           4672    224K
212.216.176.0/24       4390    219K
61.128.0.0/10          3781    190K
66.58.176.187          2925    149K
218.0.0.0/11           2583    131K
220.160.0.0/11         2449    122K
219.128.0.0/12         2069    104K
72.244.167.83          2027   94761
221.216.0.0/13         1909   94116

This is very similar to last week's numbers, down to the first place finisher.

• 218.254.83.47 returns from last week.
• 67.42.71.124 is on the DSBL.
• 66.58.176.187 and 72.244.167.83 are both 'dialup' machines as far as we can tell from their generic DNS names.

Connection time rejection stats:

  35861 total
  17407 dynamic IP
  14992 bad or no reverse DNS
   2390 class bl-cbl
    278 class bl-dsbl
    135 class bl-sdul
     81 class bl-njabl
     69 class bl-sbl
     63 class bl-ordb

Out of curiosity, I took a look at the SBL rejections; the results are kind of depressing. The 69 rejections were of 13 different IP addresses; only two IP addresses (5 rejections total) were not listed for being advance fee fraud sources.

Twelve out of the top 30 most rejected IP addresses were rejected more than 100 times; the top rejection source was our friend 218.254.83.47 (497 times before it was re-blocked at the kernel level). 26 of the top 30 most rejected IP addresses are currently in the CBL; six of them are currently in bl.spamcop.net.

Hotmail is backsliding; perhaps I should be surprised. This week's stats:

• 1 message accepted, which was spam (I know, because I got it).
• 1 message rejected because it came from a non-Hotmail email address.
• 10 messages sent to our spamtraps.
• no messages refused because their sender addresses had already hit our spamtraps.
• 1 message refused due to its origin IP address being in the CBL.

The last set of numbers:

what	# this week	(distinct IPs)	# last week	(distinct IPs)
Bad HELOs	597	48	448	49
Bad bounces	30	26	10	10

Oh well, so much for not getting very many bounces. (I suppose this still qualifies by other people's standards). As with last week, (just) over half the bad HELOs came from 213.123.26.0/24, btconnect.com's outgoing SMTP server pool. The odds of this changing any time soon seems low.