Computer security remains an important issue in the management of organizational information systems. Losses resulting from computer abuse and errors are substantial, and IS managers continue to cite security and control as a key management issue. With continued expansion of clistributed data processing and storage, the need to both prevent and detect violations also increases. This latter aspect, detection of computer abuse incidents, is the focus of this study. This empirical study examines the prevalence and sophistication of security software system installations across the United States. Using a victimization survey of 528 randomly-selected DPMA members, the study examines discovered incidents of computer abuse in organizations and attempts to identify relationships between comprehensive (i.e., sophisticated) security software and successful discovery of abuse. More comprehensive security software was found to be associated with greater ability to identify perpetrators of abuse and to discover more serious computer abuse incidents. Larger organizations used both a greater number and more sophisticated security software systems than smaller organizations. Wholesale/retail trade organizations used less comprehensive software than average, while manufacturing organizations and public utilities used more comprehensive software. Surprisingly, no relationships were found between the maturity of an organization's security function and the number and/or sophistication of security software systems utilized.