Threat Detection
In computer security, a threat is a possible danger that might exploit a vulnerability to breach security and therefore cause possible harm.
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Origin
The practice emerged alongside the first networked computers. In 1971, programmer Bob Thomas created Creeper, the first self-replicating program to spread across ARPANET; in response, Ray Tomlinson wrote Reaper — the first program designed explicitly to detect and delete a threat. Commercial antivirus software followed in the 1980s, and the U.S. Computer Fraud and Abuse Act of 1986 gave threat detection legal standing as a formal discipline.
Updated February 22, 2026