The first cyberattack took place nearly 200 years ago in France
France created a national mechanical telegraph system in the 1790s; in 1834, a pair of crooked bankers named François and Joseph Blanc launched the first cyberattack, poisoning the data that went over the system in order to get a trading advantage in the bond market.
Tom Standage has a great stock-in-trade in this kind of story; his 1998 book The Victorian Internet was a fabulous look at the parallels between the telegraph bubble and the internet bubble of the late 1990s; his 2006 essay cataloged the predecessors of the moral panic over video games (like the waltz and the novel); he's written about the great handwringing over the Facebook of the 17th century (cafe society); and his 2013 book The Writing on the Wall traces "the first 2,000 years of social media" ("from the papyrus letters that Roman statesmen used to exchange news across the Empire to the advent of hand-printed tracts of the Reformation to the pamphlets that spread propaganda during the American and French revolutions" ).
His essay on the first cyberattack is an excellent Standage riff, combining the technical (the crooks exploited a bug in how the backspace characters were handled by the mechanical telegraph) with the economic and social, and revealing lessons from history that bear close reading today.
More by Cory Doctorow at:
https://boingboing.net/2018/05/28/paleohackers.html