Frequently Asked Questions

US-CERT offers answers to some of the many common questions about the US-CERT mailing lists and website. Click on a subject heading below to view questions and answers relating to your selection. Links throughout the answers will guide you to further information on our website or from other sources. Should you have any further questions, please refer to our Contact Us page.

Mailing List Questions

What is the National Cyber Awareness System?

The National Cyber Awareness System is America's first cohesive national cyber security system for identifying, analyzing, and prioritizing emerging vulnerabilities and threats. Managed by the US-CERT, the system relays computer security update and warning information to all users. It provides all citizens—from computer security professionals to home computer users with basic skills—with free, timely, actionable information to better secure their computer systems. The National Cyber Awareness System provides valuable cyber security information in the form of Alerts, Tips, and Bulletins.

What mailing lists are available, and how do I subscribe?

You can sign up to receive Alerts, Tips, and Bulletins, and Current Activity updates through email. Visit the subscription system to subscribe to one or more of the lists.

I'm having trouble subscribing to a mailing list; what can I do?

If you are having difficulties subscribing to receive any of the cyber alert products, check to see if any of these situations apply to you:

  • Does your email program put an automatic message on the end of all of my outgoing email messages?

    Some email programs append special messages to each outgoing message. If you know that your email program does this, you can still subscribe to any of the US-CERT mailing lists. When you compose your subscription request, type "end" as the last line in the body of the message. For example, if you are subscribing to receive technical alerts, the body of your message would look like this

    Subscribe technical-alerts 

  • Did you confirm your subscription?

    As part of the security checks for the email subscription list, after you send your initial request, you will be asked to send back a confirmation of this request. The confirmation number that you received from must be in the subject line of the message.

If you are still having trouble subscribing, send a detailed message to describing the steps you took to subscribe. It is also helpful to include the text of any messages you sent and received regarding your subscription.

How do I change my email address?

If you wish you change your email address, you will have to unsubscribe with your old address and subscribe with your new address. See How do I unsubscribe from a mailing list? for specific instructions.

How do I unsubscribe from a mailing list?

  1. Open your email client and choose the option to compose a new email message
  2. In the To: field, type
  3. In the Subject: field, type unsubscribe
  4. In the Body of the message, type one of the following options, substituting the email address you are unsubscribing for the example text:

    unsubscribe technical-alerts
    unsubscribe security-tips
    unsubscribe security-bulletins
    unsubscribe current-activity

    Note: You do not need to send the email from the account you are unsubscribing.

  5. Remove any additional text from the body of the message, including a signature line (if your email client automatically adds a signature when you send the message, disable this feature or type end at the bottom of your message)
  6. Send the email (this does not complete the process)
  7. Check your email at the address you are unsubscribing for a message from US-CERT asking you to confirm the change
  8. Reply to the message (make sure the confirmation number appears in the Subject: of the message), adding one of the following words to the beginning of the Body of the email:


    Note: If you cannot send email from the address you are unsubscribing, you can copy the information into a message sent from your active email account. Make sure the correct confirmation number appears in the Subject: and either accept or reject appears in the Body.

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Website Questions

Is the US-CERT site secure?

The website employs adequate security to ensure that the documents stored on the site are safe from viruses. If you require an additional level of security, you can use the mirror site that uses a secure socket layer under the regular HTTP application. That URL is

What are the terms of use for the US-CERT site?

The US-CERT website contains a full description of our terms of use.

What is the privacy policy for the US-CERT site?

The US-CERT website contains a full description of our privacy policy.

How can I send secure information to US-CERT?

You can encrypt information you send to US-CERT through email. Find out more about communicating with US-CERT via email at

Does US-CERT provide RSS or Atom feeds for its web content?

US-CERT currently provides Atom feeds for the following content:

  • Alerts
  • Bulletins
  • Tips
  • Current Activity

To learn about US-CERT feeds and how to subscribe to them, see More About US-CERT Atom Feeds.

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