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CERT Incident Note IN-98.03

The CERT Coordination Center publishes incident notes to provide information about incidents to the Internet community.

Password Cracking Activity

DATE: Thursday, July 16, 1998

In an incident recently reported to the CERT/CC, a very large collection of password files was found on a compromised system.

In total, the intruder appears to have a list of 186,126 accounts and encrypted passwords. At the time the password file collection was discovered, the intruder had successfully guessed 47,642 of these passwords by using a password-cracking tool.

Since most of the entries did not come from the site where the collection was found, it appears that they were collected from other sites by the intruder. While some of the password files included information identifying the site where the file originated, over 160,000 of the entries include only a userid and an encrypted password.

If your site could have been identified as involved in this incident, the system administrator of the compromised host would have already contacted you regarding this activity.

The collection is reported to contain entries from at least one password file that was originally shadowed. The intruder is also reported to have a collection of passwords that appear to have been obtained using network sniffing software. This list of passwords is apparently being used as input to the password-cracking tool.

If you are interested in more information about protecting your systems against password-cracking attacks, you may want to review our Tech Tip on this topic:

http://www.cert.org/tech_tips/passwd_file_protection.html

This document is available from: http://www.cert.org/incident_notes/IN-98.03.html

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