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Alert Regarding Published Reports of Attacks on the Domain Name System

LOS ANGELES – 15 February 2019 – The Internet Corporation for Assigned Names and Numbers (ICANN) today announced that it is aware of several recent public reports regarding malicious activity targeting the Domain Name System (DNS). We have no indication that any ICANN organization systems have been compromised, and we are working with relevant community members to investigate reports of attacks against top-level domains (TLDs). For some reporting on this issue, please refer to these sources:

ICANN believes it is essential that members of the domain name industry, registries, registrars, resellers, and related others, take immediate proactive and precautionary measures, including implementing security best practices, to protect their systems, their customers’ systems and information reachable via the DNS.

We trust that DNS industry actors are already taking strong security precautions in your business. However, here is a checklist to consider.

  • Ensure all system security patches have been reviewed and have been applied;
  • Review log files for unauthorized access to systems, especially administrator access;
  • Review internal controls over administrator (“root”) access;
  • Verify integrity of every DNS record, and the change history of those records;
  • Enforce sufficient password complexity, especially length of password;
  • Ensure that passwords are not shared with other users;  
  • Ensure that passwords are never stored or transmitted in clear text;
  • Enforce regular and periodic password changes;
  • Enforce a password lockout policy;
  • Ensure that DNS zone records are DNSSEC signed and your DNS resolvers are performing DNSSEC validation;
  • Ideally ensure multi-factor authentication is enabled to all systems, especially for administrator access; and
  • Ideally ensure your email domain has a DMARC policy with SPF and/or DKIM and that you enforce such policies provided by other domains on your email system.

The Security and Stability Advisory Committee (SSAC) previously published advice and information on security best practices relevant to this threat:

ICANN strives to be a trusted partner in the multistakeholder community, and engage in collaborative efforts to ensure the security, stability and resiliency of the Internet’s global identifier systems. For more information on ICANN’s role in the security, stability and resiliency of the Internet’s identifier systems, visit https://www.icann.org/octo-ssr.

The ICANN community will continue the discussion on this critical topic at its upcoming ICANN64 meeting in Kobe. In addition, ICANN org is available to provide consultation on security best practices by emailing globalsupport@icann.org.

About ICANN

ICANN's mission is to help ensure a stable, secure, and unified global Internet. To reach another person on the Internet, you need to type an address – a name or a number – into your computer or other device. That address must be unique so computers know where to find each other. ICANN helps coordinate and support these unique identifiers across the world. ICANN was formed in 1998 as a not-for-profit public-benefit corporation with a community of participants from all over the world.


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Domain Name System
Internationalized Domain Name ,IDN,"IDNs are domain names that include characters used in the local representation of languages that are not written with the twenty-six letters of the basic Latin alphabet ""a-z"". An IDN can contain Latin letters with diacritical marks, as required by many European languages, or may consist of characters from non-Latin scripts such as Arabic or Chinese. Many languages also use other types of digits than the European ""0-9"". The basic Latin alphabet together with the European-Arabic digits are, for the purpose of domain names, termed ""ASCII characters"" (ASCII = American Standard Code for Information Interchange). These are also included in the broader range of ""Unicode characters"" that provides the basis for IDNs. The ""hostname rule"" requires that all domain names of the type under consideration here are stored in the DNS using only the ASCII characters listed above, with the one further addition of the hyphen ""-"". The Unicode form of an IDN therefore requires special encoding before it is entered into the DNS. The following terminology is used when distinguishing between these forms: A domain name consists of a series of ""labels"" (separated by ""dots""). The ASCII form of an IDN label is termed an ""A-label"". All operations defined in the DNS protocol use A-labels exclusively. The Unicode form, which a user expects to be displayed, is termed a ""U-label"". The difference may be illustrated with the Hindi word for ""test"" — परीका — appearing here as a U-label would (in the Devanagari script). A special form of ""ASCII compatible encoding"" (abbreviated ACE) is applied to this to produce the corresponding A-label: xn--11b5bs1di. A domain name that only includes ASCII letters, digits, and hyphens is termed an ""LDH label"". Although the definitions of A-labels and LDH-labels overlap, a name consisting exclusively of LDH labels, such as""icann.org"" is not an IDN."