Argentinian police have arrested a 19-year-old man on suspicion of running a cybercriminal gang that targeted the websites of money transfer and gambling firms.
The unidentified man has been dubbed the "Superhacker" and is the son of an IT engineer.
The teen was making $50,000 (30,000) from the racket every month, according to estimates.
Police detained the suspect as part of "Operation Zombie". Law enforcement officers also raided five other locations in Buenos Aires and the city of Rosario, 300 kilometres north.
It took police a year to find the hacker. When they did, police said they seized sophisticated computing equipment.
It was alleged hackers used malware to build up a botnet of computers, which was used to illegally divert money from accounts and left virtually no trace behind. While the heist took place, a denial of service was also carried out to prevent victims accessing their accounts.
Police have also identified six other people they believe were involved in the scheme.
Operation Zombie began last year when a hosting company said servers it ran were being remotely accessed to intercept money transfers.
Argentina's chief prosecutor Graciela Gils Carbo ordered a federal investigation. It was later discovered that the same group was stealing money from other sites as well.
"Internet users were victims of a malware virus that the hacker hosted in a server for downloading online gaming applications," read a statement from Argentina's Security Ministry.
If convicted, the man could be sentenced to over 10 years in prison.
