Viruses and Other Software Threats › Understanding Software Threats › What Is a Trap Door?

What Is a Trap Door?

A trap door is a method of gaining access to information or z/OS features that are normally beyond a user’s access authority. The distinguishing feature of a trap door is that it is intentionally hidden and used only when needed. The trap door is often a special command, available only to those users who know how to activate it.

Trap doors are very popular in the z/OS mainframe world. Unfortunately, your data center’s own technical support staff members can put them into z/OS for various reasons. The most common reasons are that the systems programmers want to:

• Install z/OS maintenance without performing an IPL
• Issue operator commands from their TSO terminals
• Bypass the security system in case they need to perform system diagnosis or repairs off‑shift

Trap doors circumvent established controls and expose the system to other threats, such as viruses and logic bombs. You can impact the reliability of your z/OS system by ad hoc updating of system modules and control blocks that inadvertently damage the system. Your computer operators cannot maintain control of your system when users are submitting master console commands from TSO terminals anywhere in the network. Your security officer cannot successfully keep out hackers, thieves, other outsiders, or unauthorized insiders if they can bypass your security system.