Summary

There is no virus by this name.

However, we sometimes get queries about this, as some mail clients (notably Netscape Mail) displays an error message like this:

The POP3 server responded: Received Kiss of Death Please enter a new password
This means that the mailbox has been opened more than once concurrently.

Additional Details

This commonly occurs when, while in the process of downloading new mail, a second request for new mail is made.

The second request is often made by mail reader software's "auto-check" feature. The is especially true when your mail file is unusually large. This can be avoided simply by setting the mail reader software to not automatically check for mail.

This also may occur by manually checking for new mail while still in the process of downloading mail from a previous request for new mail -- For example, repeatedly clicking the "Get Mail" button.

Also, notably, when the Netscape Mail window is initially opened, a single request is made to get all new mail. Clicking the "Get Mail" button while this is first request is being processed causes the mailbox to be opened a second time. Viola! The "Kiss of Death."

In a Nutshell:

Disable your mail reader's "auto-check" feature.
Make a single request to get new mail
Wait for the process to complete
Avoid very large mail attachments
[Description by MHH and WeirNet, http://www.weir.net/]