Books written for IS auditors often cover platforms used by large organizations that are not in vogue with hackers. An IS auditing manual published default data for a powerful logonid in IDMS, a database still used by large organizations for production and financial data. Hundreds of millions of users have access to this information on the Internet, in computer books and vendor manuals, and other areas. Default passwords are easy to use. Many, like the Unix root account, are extremely powerful.
Unauthorized accesses are difficult to audit, because they obscure the audit trail.
If defaults are not specifically assigned to a user, accountability is lost. It would be impossible to determine who is actually using them. Finally, most platforms have some defaults. Default passwords are a security threat no information systems manager can ignore. Resource Access Control Facility, Security Administrator's Guide, Version 2 Release 2.