Now that I've automated almost all of the Hotmail spam report, of course it turns out we've had a quiet week, even more so than last week:

• no messages accepted.
• 22 messages rejected because they came from non-Hotmail email addresses.
• 54 messages sent to our spamtraps.
• 13 messages refused because their sender addresses had already hit our spamtraps.
• 5 messages refused due to their origin IP address (one in the SBL, one in the CBL, one from Nigeria, one from Gilat-Satcom, and one from SAIX).

All of these are down from last week, although not always by huge amounts. Hopefully this will continue, although I note that for all the low numbers Hotmail is still batting 94 to nothing this week. And insisting that people jump through hoops to report Hotmail spam.

The basic stats:

• got 13,656 messages from 222 different IP addresses.
• handled 25,483 sessions from 2,261 different IP addresses.
• received 156,390 connections from at least 50,712 different IP addresses.
• a highwater of 27 connections being checked at once.

Everything is slightly down from last week except for the number of different IP addresses doing SMTP sessions. The per day table is slightly interesting this week:

Day	Connections	different IPs
Sunday	23,590	+7,935
Monday	22,349	+8,156
Tuesday	24,991	+7,396
Wednesday	26,030	+7,478
Thursday	22,129	+7,239
Friday	21,328	+7,187
Saturday	15,973	+5,321

Someday, someone is going to do a fascinating article on what days spammers prefer for their spam runs, and why. Have the spammers done 'market research' on what days get the best results, for example?

Kernel level packet filtering top ten:

Host/Mask           Packets   Bytes
69.90.73.20            5785    347K
212.216.176.0/24       4821    237K
61.128.0.0/10          3479    181K
219.128.0.0/12         2635    138K
80.128.0.0/12          2409    139K
220.160.0.0/11         2234    114K
69.223.241.2           2178    111K
24.147.105.129         2097    101K
221.216.0.0/13         2073    105K
218.0.0.0/11           2004    102K

This is a slow week for individual IP addresses; only three made it into the top ten. 24.147.105.129 reappears from last October, because it is still listed in SPEWS. 69.90.73.20 and 69.223.241.2 both got blocked for lots of unresolvable HELOs.

The 80.128.0.0/12 area belongs to Deutsche Telekom and made the list last December; I've seen nothing since then that makes me reconsider our permanent blocks. All the other netblocks listed belong to various Chinese networks.

Connection time rejection stats:

  26730 total
  13007 dynamic IP
   8886 bad or no reverse DNS
   3056 class bl-cbl
    488 class bl-spews
    319 class bl-ordb
    232 class bl-dsbl
    125 class bl-sbl
     53 class bl-sdul
     48 class bl-njabl
      4 class bl-opm

Somewhat down from last week, and much more evenly distributed among different IP addresses; only 4 IP addresses were refused 100 times or more, and the winner (218.210.168.102, a Taiwanese IP address blocked for bad reverse DNS) only managed 135 times. Six of the 30 most refused IPs are in the CBL and five are currently in bl.spamcop.net; none are in the SBL this week.

Interestingly, exactly 100 refused IPs are in the SBL at the moment, in 62 different SBL listings. Here's the top hits:

# of different IPs	SBL listing	listed:	who/what
8	SBL22806	19-Feb-2006	de.clara.net advance fee fraud
7	SBL37830	12-Feb-2006	Philippines based spammer hosting
7	SBL35573	09-Dec-2005	CNCGROUP Beijing
5	SBL37409	07-Feb-2006	Japanese spam source
4	SBL35873	16-Dec-2005	mailyes.net, Korean spam source (under bora.net)
4	SBL19307	28-Aug-2005	a /16 listing for a Chinese spam injection network
3	SBL37888	14-Feb-2006	Korean spam sources (dacom.net)
3	SBL37860	13-Feb-2006	'Clear Reach Networks' spam network (SAVVIS)
3	SBL37388	28-Jan-2006	Ephedra spammers, 'Plumtree Solutions' (UUNet)

I find it heartening that none of these are ROKSO-listed spammers, and most of the listings are less than a month old (and that the oldest only dates to August 2005). Unfortunately, SpamHaus doesn't make their listings really easily queryable, so I can't report what the oldest SBL listing to hit us this week is.

what	# this week	(distinct IPs)	# last week	(distinct IPs)
Bad HELOs	6167	364	8423	248
Bad bounces	1994	1031	815	558

Spammers are clearly still forging us and there's a lot of quite active mail servers with unresolvable HELO names, although only nine tried 100 times or more. The standout winner for 'most backscatter' goes to 66.83.181.196 (349 hits), followed by 69.37.62.196 (199 hits) and 67.107.40.2 (111 hits). Backscatter is one of those things that makes me grind my teeth, given that we're forged so often by spammers.