SURBL Lists

SURBLs contain web sites which appear in unsolicited messages. They can be used with programs that can check message body URIs (web sites mentioned in the message body) against a list such as SpamAssassin 3 and others mentioned on the links page.

Here's an overview of the lists and their data sources.

sc.surbl.org - SpamCop message-body URI domains

sc.surbl.org contains domains and a few web site IP addresses processed from SpamCop URI reports, also known as "spamvertised" sites. The reports are not used directly, but are subject to extensive processing. Entries in sc.surbl.org expire automatically several days after the SpamCop reports decrease.

Note that this list is not the same as bl.spamcop.net, which is a list of mail sender IP addresses found in message headers.

ws.surbl.org - sa-blacklist and other sources

ws.surbl.org has records from Bill Stearns' former SpamAssassin ruleset sa-blacklist, plus some other manual lists. Bill's policy for inclusion and cleaning of the sa-blacklist is quite sound, though it differs somewhat from some of the other SURBLs. ws and sc seem to detect some different types of sites so by using both lists together they should to complement each other well.

Advantages of turning SA rulesets into SURBLs

Using SURBLs derived from SpamAssassin rulesets instead of the rulesets offers several advantages. First, there is less memory usage in SpamAssassin, since a potentially large set of rules is not loaded, instead being cached in your local name server. Second, since data in SURBLs are no longer tied to SpamAssassin, they can be used in other programs that can check message body URIs against an list, such as MTA plugins, etc. Third, updates tend to be more timely since a DNSBL can be updated automatically in a few minutes with generally low overhead. So applications using SURBLs gain efficiency, modularity, portability, and speedy, automatic updates.

SURBL and Bill Stearns strongly recommend using SURBLs instead of sa-blacklist as a SpamAssassin ruleset. Anyone using sa-blacklist should migrate to using SURBLs instead. SURBLs are supported in SpamAssassin version 3 and later.

ob.surbl.org - Outblaze URI Blacklist

Outblaze is kindly providing their internal URI blacklist which is published as ob.surbl.org. The list is detecting about 70% of unsolicited messages while triggering about 0.05% false positives.

Outblaze describes the data as coming from spam trap message body analysis and from user reports via a "this is spam" button. SURBL applies additional policies to its version of the Outblaze URI data that are published as ob.surbl.org. The user reports are also used, but not directly.

Note that Outblaze's sender IP blacklist, which is visible on their web site, is not the same as their URI blacklist. The SURBL list is based on their separate URI blacklist which is not visible on their web site.

Please send removal requests for ob.surbl.org to: postmaster at outblaze dot com. Be sure to include all of the list removal information.

ab.surbl.org - AbuseButler Spamvertised Sites

AbuseButler is kindly providing its top 400 or so Spamvertised Sites which have been most often reported over the past 7 days. The philosophy and data processing methods are similar to the sc.surbl.org data, and the results are similar, but not identical.

Data sources for AbuseButler include SpamCop and native AbuseButler reporting.

ph - Phishing data source

The Anti-Phishing Working Group has a good definition of phishing on their web site. Phishing data from multiple sources are included in the ph Phishing data source. It should be useful for identifying phishing messages, and its use is encouraged. Unlike other SURBLs, phishing data includes a few deliberate subdomains, as found in URIs. (Because SURBL applications are expected to reduce subdomains to base domains, an occasional mismatch in domain levels between data and application should not cause false positives.)

Phishing data were initially provided by MailSecurity. As of November 2004, we have added data from fraud.rhs.mailpolice.com into ph. Thanks to Jay Swackhamer of MailPolice for gathering this data and making it available to us. As of mid-2006, were are including phishing data from Castlecops' PIRT. As of October 2006, we are also adding PhishTank data to our phishing list. As of December 2007, we have added The DNS blackhole malware, malicious software and phishing site data from malwaredomains.com to our phishing list. As of April 2008, the list also includes Malware Block List data from malware.com.br.

jp - jwSpamSpy + Prolocation data source

Joe Wein's jwSpamSpy program forms the basis of the JP data, being used both by Joe's own systems and also Raymond Dijkxhoorn and his colleagues at Prolocation. Prolocation is processing more than 300,000 likely unsolicited messages per day using jwSpamSpy plus their own policies and adding them to Joe's data. The resulting list has a very good detection rate around 80% and a very low false positive rate around 0.01%.

JP is included in the default configuration of SpamAssassin 3.1 and other SURBL applications.

multi.surbl.org - Combined SURBL list

All of the SURBL data sources are combined into a single, bitmasked list: multi.surbl.org. Bitmasking means that there is only one entry per domain name or IP address, but that entry will resolve into an address (DNS A record) whose last octet indicates which lists it belongs to. The bit positions in that octet for the different lists are:
2 = comes from sc.surbl.org
4 = comes from ws.surbl.org
8 = comes from phishing data source (labelled as [ph] in multi)
16 = comes from ob.surbl.org
32 = comes from ab.surbl.org
64 = comes from jp data source (labelled as [jp] in multi)
If an entry belongs to just one list it will have an address where the last octet has that value, for example 127.0.0.8 means it comes from the phishing list and 127.0.0.2 means it's in the data used in sc.surbl.org. An entry on multiple lists gets the sum of those list numbers as the last octet, so 127.0.0.6 means a record is on both ws.surbl.org and sc.surbl.org (comes from: 2 + 4 = 6). In this way, membership in multiple lists is encoded into a single response.

Please use multi and not the individual lists, since using multi combines potentially several queries into a single one, reducing DNS overhead. The individual lists may be deprecated at some point in future. Every SURBL application should use multi only. We recommend using this combined list with programs that can decode the responses into specific lists, such as SpamAssassin 3's urirhssub or SpamCopURI version 0.22 or later for use with SpamAssassin 2.64.

Default TTL for the live data in the combined list is 15 minutes.

Each entry also has a TXT record mentioning which lists it is on, and pointing to this page. While we expect the TXT records to be relatively stable, we recommend that automatic processing be based on the A record.

Other SURBLs

Other lists may become available as future SURBLs. Please check back here occasionally or on our Announce mailing list for updates.

List Removal

All of the data in SURBL lists come from external data sources. None of the SURBL lists come from data created here, so generally speaking to get a record off a list you should contact that data source as described earlier under each list. For the Outblaze URI blacklist which feeds into ob.surbl.org (OB), please contact: postmaster at outblaze dot com . (Please do not contact Outblaze for domains that do not appear on the Outblaze URI blacklist.) For the ph.surbl.org phishing list (PH), please be sure to remove all phishing sites, cracked accounts, viruses, malware loaders, trojan horses, compromised Windows, unpatched Linux, insecure PHP boards, cracked SQL, etc., from your server and secure it before writing. For SURBL lists other than OB you may send a removal request to: whitelist at surbl dot org . When sending a removal request:
  1. Please check that the domain you are reporting is actually on a SURBL list. This can be done for example by using the SURBL+ checker tool or with a name resolution. Note that there is rare bug with SpamAssassin versions before 3.1 that appears to show list inclusion when none actually exists. (See SpamAssassin Bugzilla id=3997, and note that this bug is fixed starting with SpamAssassin version 3.1.) Note also that some DNS modification services and spam/phishing protection proxies may not be compatible with SURBL applications if they change certain responses to DNS queries.

    and please include:

  2. The domain name you are reporting. Include the domain name in the subject of your message.
  3. The SURBL list it appears on (Note that multi.surbl.org is not the list. The list will have two letters like WS or OB.)
  4. Full and complete contact information for your organization including street address and telephone numbers
  5. IP address or network of your outbound mail servers (usually this is not the same as your web server)
  6. A typical message advertising your site with full headers and full message body including URIs all pasted in as inline plain text and not an attachment
  7. A description of your organization or the web site
  8. Your organization's published mail practices, especially its published policies against advertising its web site in unsolicited messages, regardless of how they are sent or who sends them. (SURBLs are lists of web sites, not lists of mail senders.) If your organization does not publish and practice an anti-spam policy, it should. Search for "spam policy," and you will find many.
  9. If any of your affiliates, customers, agents, partners or third party mailers advertises your domain in unsolicited messages, then your domain may be blacklisted. It is your responsibility to control their use of your domains and sites. This is confirmed in FTC enforcement of the CAN SPAM law in the U.S. for example.
  10. You and your affiliates should follow best current practices for mailing such as those published by the Canadian Federal Task Force on Spam, Messaging Anti-Abuse Working Group (MAAWG) Sender Best Communications Practices, LINX Best Current Practice for the running of mailing lists, or MAPS Guidelines for proper mailing list management. A more marketing-oriented site can be found at ClickZ. Senders who use well-established standard practices such as these will be considered for removal. In particular the safest way to use a mailing list is to confirm all additions, that is, do not send mail to any address that has not positively confirmed that it wants to get mail from you. Buying or renting addresses from a third party definitely should be avoided since it's often difficult to know whether permission has been obtained.
    If organizations have not obtained the express consent of recipients prior to sending [unsolicited commercial email], then they are sending spam.
    Canadian Federal Task Force on Spam
  11. Please send your request from your organization's domain. Requests sent from Hotmail, Yahoo, gmail, etc., accounts may not be considered.
  12. Please use plain text when writing, not proprietary or encoded formats like Word, pdf, etc. Do not send attachments.
  13. If your domain or IP address is on the ph.surbl.org phishing list, it usually means that your web server has been cracked and is hosting a phishing or malware (virus, trojan horse, worm, etc.) site. Please remove the phishing or malware site and secure the server before contacting us. Please note that we cannot provide security consulting or systems administration. Please contact a security expert if you need help.
  14. You are urged in the strongest possible terms to positively confirm subscriptions as described in the best practices documents above. Unconfirmed subscriptions are often abused by third parties to maliciously add other addresses without their consent or permission. When this happens your mailing lists are corrupted with addresses that do not want to get your messages. Confirmations almost always prevent this common type of abuse.
Please send removal requests to whitelist at surbl dot org . For sites on the ob.surbl.org list, please send requests to postmaster at outblaze dot com .

<< Data Previous Section, Next Section Implementation >>

lists.html version 2.27 on 4/28/08