To put it short, for about a month, I see a new kind of spam
coming to (strangely) just one of my (many) mailboxes. This one
has DKIM-Signature: (and DomainKey-Signature:) headers in place,
comes from domains with SPF and MX DNS records properly set up,
and, overall, apart from its "unsolicited nature," looks just
like legitimate email. (IPs and MAIL FROM: data shown below.)
There're some characteristics common to all these messages,
however, hinting at possible "common origin" (be it person,
organization, or specific software used.) For instance:
* all the Message-ID: headers follow the same [0-9A-F]{32}@HOST
pattern;
* the domains are all under the "ru" ccTLD, and all registered
via NETHOUSE-RU; also, most were created February or March
this year, but some (r-vl.ru, sarvtb.ru, sm-1.ru,
taxi-five.ru) are just a few days old, created on 2016-10-01;
* all the IPs the messages come from belong to MAROSNET.
I've sent a letter last week reporting the issue to abuse at
marosnet dot ru (per the Whois data), but yet to see any
response.
Meanwhile, I've configured the firewall to drop any traffic from
the addresses in question (but also log incoming TCP "SYN"
connection attempt packets.)
For those interested, the IPs and MAIL FROM: data is as follows
(per ISO week.)
$ gawk '! /\sid=[0-9A-Z]{32}@/ { next; }
1 {
"date +%GW%V --date=" $1 "T" $2 | getline key;
save[key] = save[key] "\t" $5 " " $7 "\n";
}
END {
PROCINFO["sorted_in"] = "@ind_str_desc";
for (key in save) { print key "\t" save[key]; }
}' /var/log/exim...
2016W40 nzbhuf@sarvtb.ru [185.58.205.96]
hlkkn@proteus-spb.ru [194.67.208.8]
rerxboy@kaminfo.ru [193.124.176.209]
jaqxujp@r-vl.ru [185.58.206.163]
njlcyy@sab-moskau.ru [193.124.190.134]
feud@taxi-five.ru [185.58.206.232]
2016W39 bcswvsv@network-asp.ru [194.67.208.143]
yyl@sinex-real.ru [194.67.208.219]
sstyqp@network-asp.ru [194.67.208.143]
yqe@karaaltyn.ru [194.67.210.159]
qbinq@cameraforme.ru [185.87.48.186]
maq@lagorta.ru [193.124.191.224]
szzliot@sinex-real.ru [194.67.208.219]
iuqdjn@intra-m.ru [94.142.141.60]
jkety@eureka-service.ru [193.124.186.253]
vvpxww@karaaltyn.ru [194.67.210.159]
gylay@sirius-87.ru [194.67.208.224]
lhhg@eureka-service.ru [193.124.186.253]
rgi@sinex-real.ru [194.67.208.219]
qhtlw@karaaltyn.ru [194.67.210.159]
uavvf@cameraforme.ru [185.87.48.186]
bue@network-asp.ru [194.67.208.143]
jmpdlx@lambdafsu.ru [193.124.189.172]
tgan@biomedex.ru [193.124.189.192]
zxxemip@kaminfo.ru [193.124.176.209]
mnvi@lambdafsu.ru [193.124.189.172]
lcsktjt@sab-moskau.ru [193.124.190.134]
swsxv@securityprint.ru [185.5.248.60]
vbqd@sm-1.ru [185.58.206.76]
kxrjc@ghtersale.ru [194.67.208.7]
2016W38 pvtll@mtvigroup.ru [194.67.208.216]
cpdve@php-art.ru [194.67.209.151]
lhona@sirius-87.ru [194.67.208.224]
hqphzjp@lagorta.ru [193.124.191.224]
mewmb@cristallgrad.ru [185.87.48.131]
dxb@php-art.ru [194.67.209.151]
zadh@lagorta.ru [193.124.191.224]
2016W37 bct@butovo-net.ru [194.67.210.18]
tjlwhlp@carveryachts.ru [85.93.145.29]
orgf@butovo-net.ru [194.67.210.18]
luaj@olympus-team.ru [194.67.209.7]
fagvf@polexpack.ru [194.67.208.220]
cxjqyrw@polexpack.ru [194.67.208.220]
uyhtz@siae.ru [194.67.209.56]
mlfpawb@delst.ru [194.67.208.249]
jgt@php-art.ru [194.67.209.151]
fakeb@instaltek.ru [194.67.208.232]
2016W36 vziykt@tyumfair.ru [194.67.208.60]
rvn@fordlimo.ru [194.67.208.50]
kqeoin@r-c-g.ru [194.67.208.101]
vkf@e-dvd.ru [194.67.210.222]
mwodhs@lk-prom.ru [194.67.211.17]
otpqos@avtobogatir.ru [194.67.210.2]
David Ritz <dritz@mindspring.com> writes:
Ivan Shmakov <ivan@siamics.net> wrote:
[ news.admin.net-abuse.email added to cross-post ]
[ alt.spam stripped as group only sees spam, spam, spam and more spam ]
[ alt.spam.sightings stripped as bogus (newgrouped by Jamie Baillie) ]
[ <ftp://ftp.isc.org/pub/usenet/control/alt/alt.spam.sightings.gz> ]
[ posted and mailed ]
To put it short, for about a month, I see a new kind of spam coming
to (strangely) just one of my (many) mailboxes. This one has
DKIM-Signature: (and DomainKey-Signature:) headers in place, comes
from domains with SPF and MX DNS records properly set up, and,
overall, apart from its "unsolicited nature," looks just like
legitimate email. (IPs and MAIL FROM: data shown below.)
Neither SPF nor DKIM say anything about whether mail is unsolicited
and bulk. These are forgery abatement measures. The only things
which might be determined from SPF and DKIM is whether or not mail originated via a sender allowed host; nothing more, nothing less.
Of those host I checked, which still resolve, most are listed by the psbl.org, barracudacentral.org and/or uceprotect.net DNSbls, with a smattering of SBLCSS (snowshoe) and Spamcop listings. All indicate
the IP addresses you list are spam sources,
where SPF and DKIM say that the sending domain is authorized to send
via these spammer controlled, dirty IP addresses.
2016W40 nzbhuf@sarvtb.ru [185.58.205.96][...]
2016W39 bcswvsv@network-asp.ru [194.67.208.143][...]
2016W38 pvtll@mtvigroup.ru [194.67.208.216][...]
2016W37 bct@butovo-net.ru [194.67.210.18][...]
2016W36 vziykt@tyumfair.ru [194.67.208.60][...]
David Ritz <dritz@mindspring.com> writes:
Ivan Shmakov <ivan@siamics.net> wrote:
[Be warned of a few off-topic bits below.]
[ news.admin.net-abuse.email added to cross-post ]
[ alt.spam stripped as group only sees spam, spam, spam and more spam ]
While I understand the evil of sending spam to a high S/N ratio
group, the above seems to suggest there's something wrong with
doing it the other way around. Which is especially strange given
that (a) n.a.n.email's own S/N doesn't seem all that high, and (b)
alt.spam occasionally sees a legitimate message, too (say,
news:o2avsbphgb19dna8fv03b9r79i3dh6qace@4ax.com.)
(... And also (c) apparently, Aioe blocks crossposts to n.a.n.e;
presumably due to ongoing abuse?)
[ alt.spam.sightings stripped as bogus (newgrouped by Jamie Baillie) ]
[ <ftp://ftp.isc.org/pub/usenet/control/alt/alt.spam.sightings.gz> ]
FTP is pretty much obsolete. For one thing, requiring two
TCP connections per "session" means trouble passing them through
Tor, NAT, SOCKS, etc. And having three separate transfer modes
(at the least) doesn't help interoperability, either.
That said, the same resource is available via HTTP, too:
http://ftp.isc.org/pub/usenet/control/alt/alt.spam.sightings.gz
[ posted and mailed ]
Why?
To put it short, for about a month, I see a new kind of spam
coming to (strangely) just one of my (many) mailboxes. This one
has DKIM-Signature: (and DomainKey-Signature:) headers in place,
comes from domains with SPF and MX DNS records properly set up,
and, overall, apart from its "unsolicited nature," looks just like
legitimate email. (IPs and MAIL FROM: data shown below.)
Neither SPF nor DKIM say anything about whether mail is unsolicited
and bulk. These are forgery abatement measures. The only things
which might be determined from SPF and DKIM is whether or not mail
originated via a sender allowed host; nothing more, nothing less.
Yes. Still, both somehow get advertised as "counter-spam"
measures.
Not that they fail to work that way: my logs have some occurrences
of the SPF check yielding a "negative" result, thus allowing to
reject the incoming message outright. Looks like a must for the
DNS domains not meant to be used for email at all.
That said, being able to confirm that the message indeed comes
from a genuine spam-only domain doesn't seem all that helpful.
[...]185.58.205.96 sarvtb.ru : psbl.surriel.com : BLOCKED (127.0.0.2)
Of those host I checked, which still resolve, most are listed by the
psbl.org, barracudacentral.org and/or uceprotect.net DNSbls, with a
smattering of SBLCSS (snowshoe) and Spamcop listings. All indicate
the IP addresses you list are spam sources,
ACK, thanks for the pointers.
where SPF and DKIM say that the sending domain is authorized to send
via these spammer controlled, dirty IP addresses.
... For those interested, here's an update for this week.
2016W40 nzbhuf@sarvtb.ru [185.58.205.96]
hlkkn@proteus-spb.ru [194.67.208.8]194.67.208.8 proteus-spb.ru : psbl.surriel.com : BLOCKED (127.0.0.2)
rerxboy@kaminfo.ru [193.124.176.209]193.124.176.209 kaminfo.ru : psbl.surriel.com : BLOCKED (127.0.0.2)
jaqxujp@r-vl.ru [185.58.206.163]185.58.206.163 r-vl.ru : psbl.surriel.com : BLOCKED (127.0.0.2)
njlcyy@sab-moskau.ru [193.124.190.134]193.124.190.134 sab-moskau.ru : psbl.surriel.com : BLOCKED (127.0.0.2)
feud@taxi-five.ru [185.58.206.232]185.58.206.232 taxi-five.ru : zen.spamhaus.org : BLOCKED (127.0.0.3)
pslvslw@uralgsm.ru [185.117.155.168]185.117.155.168 uralgsm.ru : dnsbl-1.uceprotect.net : BLOCKED
yukl@nordmor.ru [193.124.181.229]193.124.181.229 nordmor.ru : zen.spamhaus.org : BLOCKED (127.0.0.3)
rgmcmxo@whdent.ru [193.124.184.229]193.124.184.229 whdent.ru : zen.spamhaus.org : BLOCKED (127.0.0.3)
itely@whdent.ru [193.124.184.229]193.124.184.229 whdent.ru : zen.spamhaus.org : BLOCKED (127.0.0.3)
vdnu@02info.ru [185.87.49.127]185.87.49.127 02info.ru : zen.spamhaus.org : BLOCKED (127.0.0.3)
mnweeg@agcher.ru [193.124.183.150]193.124.183.150 agcher.ru : zen.spamhaus.org : BLOCKED (127.0.0.3)
wdoet@fanabe.ru [193.124.181.9]193.124.181.9 fanabe.ru : zen.spamhaus.org : BLOCKED (127.0.0.3)
FWIW, I hope that whatever software they use to distribute spam
is /not/ parallelized. That way, the failure of my MTA to
produce any TCP response whatsoever (thanks to the plain -j DROP
in the iptables' INPUT chain) would result in at least some 30 s
delay (that is: their TCP connection timeout) before the next
address in the list is tried.
Ivan,[...]
I stripped out the domain names and sorted by unique IP addresses. By looking at the source IPs, one begins to see clearer paterns.
85.93.145.29
route: 85.93.144.0/20
descr: SPACENET-RU-144-20
origin: AS34300
94.142.141.60
route: 94.142.136.0/21
descr: MAROSNET Telecommunication Company Network
origin: AS48666
route: 194.67.208.0/20
descr: MAROSNET Telecommunication Company Network
origin: AS48666
My observations suggest that MAROSNET Telecommunication Company
Network is running some large scale snowshoe spam hosting services.
David Ritz <dritz@mindspring.com> writes:
I stripped out the domain names and sorted by unique IP addresses.
By looking at the source IPs, one begins to see clearer paterns.
route: 194.67.208.0/20
descr: MAROSNET Telecommunication Company Network
origin: AS48666
My observations suggest that MAROSNET Telecommunication Company
Network is running some large scale snowshoe spam hosting services.
David Ritz <dritz@mindspring.com> writes:
[...]
I stripped out the domain names and sorted by unique IP addresses.
By looking at the source IPs, one begins to see clearer patterns.
[...]
route: 194.67.208.0/20
descr: MAROSNET Telecommunication Company Network
origin: AS48666
Yes. That was the reason I've tried to contact their abuse@
department earlier.
My observations suggest that MAROSNET Telecommunication Company
Network is running some large scale snowshoe spam hosting services.
Given the sheer number of IPs, and also that my prior email
resulted in no response, that doesn't sound all that unlikely.
Thus, I've ended up blocking 185.58.204.0/22, 193.124.176.0/20
about last Saturday, and now added 185.125.216.0/22,
185.87.48.0/22, 193.124.176.0/20 and 194.67.196.0/22, too, to my
ipset(8) configuration.
As for the blacklists, I should note that I actually refer to
several in my MTA configuration, although they're used strictly to
decide whether to use graylisting or not. And indeed, some of
this spam I receive matches the DNSbls I employ, but then ends up
passing the "graylist" test successfully. (Thus suggesting the
use of a "full-weight" MTA at the remote; which is, hopefully,
means some cycles are wasted trying to connect to my firewalled
MX.)
On the other hand, some of the messages come from the addresses
/not/ yet blacklisted at the time of delivery. Perhaps the
chances could be improved by querying more blacklists for the
sender IP, though.
Once again, there's the data for the past two weeks.
2016W41 hdyuhpi@artel-site.ru [193.124.180.126]
qiluc@pampersklub.ru [185.125.216.105]
xjqhkx@mpeg-imx.ru [193.124.182.45]
xjld@jclan.ru [185.125.216.249]
jrefn@cybernsk.ru [194.67.196.156]
qnwdsl@kbidea.ru [194.67.196.163]
wapeptz@cybernsk.ru [194.67.196.156]
qqgbk@avtotera.ru [185.125.217.100]
jlotfa@vakpk.ru [193.124.190.246]
meiah@goward.ru [185.125.216.210]
lphcpx@ostankinomedia.ru [193.124.189.173]
uepowel@rti-travel.ru [185.87.51.68]
imyasa@mig-spb.ru [185.87.51.23]
ebeor@ostankinomedia.ru [193.124.189.173]
2016W40 nzbhuf@sarvtb.ru [185.58.205.96]
hlkkn@proteus-spb.ru [194.67.208.8]
rerxboy@kaminfo.ru [193.124.176.209]
jaqxujp@r-vl.ru [185.58.206.163]
njlcyy@sab-moskau.ru [193.124.190.134]
feud@taxi-five.ru [185.58.206.232]
pslvslw@uralgsm.ru [185.117.155.168]
yukl@nordmor.ru [193.124.181.229]
rgmcmxo@whdent.ru [193.124.184.229]
itely@whdent.ru [193.124.184.229]
vdnu@02info.ru [185.87.49.127]
mnweeg@agcher.ru [193.124.183.150]
wdoet@fanabe.ru [193.124.181.9]
pvv@vapnyar.ru [194.67.197.50]
David Ritz <dritz@mindspring.com> writes:
On Friday, 14 October 2016 17:50 -0000, Ivan Shmakov wrote:
David Ritz <dritz@mindspring.com> writes:
My observations suggest that MAROSNET Telecommunication Company
Network is running some large scale snowshoe spam hosting services.
Given the sheer number of IPs, and also that my prior email resulted
in no response, that doesn't sound all that unlikely.
There was a reason I included all of the upstream routes announcing
AS48666: AS9002, AS12389 and AS20485. Directing your complaints
upstream, for recalcitrant spam-hosts, is a fairly common and
sometimes useful technique.
Thus, I've ended up blocking 185.58.204.0/22, 193.124.176.0/20 about
last Saturday, and now added 185.125.216.0/22, 185.87.48.0/22,
193.124.176.0/20 and 194.67.196.0/22, too, to my ipset(8)
configuration.
As for the blacklists, I should note that I actually refer to
several in my MTA configuration, although they're used strictly to
decide whether to use graylisting or not. And indeed, some of this
spam I receive matches the DNSbls I employ, but then ends up passing
the "graylist" test successfully. (Thus suggesting the use of a
"full-weight" MTA at the remote; which is, hopefully, means some
cycles are wasted trying to connect to my firewalled MX.)
I don't know whether you're using UCEProtect among your DNSbls.
History suggests their level one (1) listings accurately list spam
sources, with a particular emphasis on spam hitting European
locations. dnsbl-1.uceprotect.net may be a useful addition for your purposes. dnsbl-2.uceprotect.net makes a statement about the
immediate net-neighborhood. dnsbl-3.uceprotect.net makes yet broader statements.
# Routes transiting through or originating from AS 48666 :
31.148.99.0/24 from AS: 48666 (upstreams: 12389 9002),
91.202.232.0/22 from AS: 48666 (upstreams: 12389 9002),
93.170.123.0/24 from AS: 48666 (upstreams: 12389 9002),
94.142.136.0/24 from AS: 48666 (upstreams: 12389 9002),
94.142.136.0/21 from AS: 48666 (upstreams: 12389 9002),
94.142.137.0/24 from AS: 48666 (upstreams: 12389 9002),
94.142.143.0/24 from AS: 48666 (upstreams: 12389 9002),
95.46.114.0/24 from AS: 48666 (upstreams: 12389 9002),
154.16.205.0/24 from AS: 48666 (upstreams: 9002 20485),
185.5.248.0/22 from AS: 48666 (upstreams: 12389 9002),
185.58.204.0/22 from AS: 48666 (upstreams: 12389 9002),
185.87.48.0/22 from AS: 48666 (upstreams: 12389 9002),
185.117.152.0/22 from AS: 48666 (upstreams: 12389 9002),
185.125.216.0/22 from AS: 48666 (upstreams: 12389 9002),
185.125.228.0/22 from AS: 48666 (upstreams: 12389 9002),
193.106.96.0/22 from AS: 48666 (upstreams: 12389 9002),
193.124.176.0/20 from AS: 48666 (upstreams: 12389 9002),
194.67.192.0/23 from AS: 48666 (upstreams: 12389 9002),
194.67.194.0/24 from AS: 48666 (upstreams: 12389 9002),
194.67.196.0/22 from AS: 48666 (upstreams: 12389 9002),
194.67.200.0/21 from AS: 48666 (upstreams: 12389 9002),
194.67.208.0/20 from AS: 48666 (upstreams: 12389 9002),
Sysop: | Keyop |
---|---|
Location: | Huddersfield, West Yorkshire, UK |
Users: | 185 |
Nodes: | 16 (2 / 14) |
Uptime: | 09:26:48 |
Calls: | 3,718 |
Calls today: | 1 |
Files: | 11,157 |
Messages: | 3,451,670 |