In 1985, a disgruntled computer security officer at an insurance brokerage firm in Texas set
up a complex series of Job Control Language (JCL) and RPG (an old programming language)
programs described later as “tripwires and time bombs.” For example, a routine data retrieval
functionwas modified to cause theIBMSystem/38 midrange computer to power down. Another
routine was programmed to erase random sections of main memory, change its own name, and
reset itself to execute a month later.
In 1992, a computer programmer was