Hacking ring steals $1B from banks worldwide, including in U.S.

A ring of hackers are believed to have stolen up to $1 billion from banks around the world, including within the United States.

The names of the affected banks haven’t yet been released, but the hackers are thought to have broken into roughly 100 financial institutions in 30 countries, according to a report to be released Monday from the Russian security company Kaspersky Lab, first reported by The New York Times.

The hackers gained access through various phishing schemes and then hung around the background for months, learning the institutions’ systems, The Times reported. Once familiar with the systems, the hackers would then program ATMs to dispense money at specific times, or they would set up fake accounts and conduct illegal transfers.

The hackers seemed to cap themselves at $10 million in thefts per bank, the newspaper reported.

“They’re flexible and quite aggressive and use any tool they find useful for doing whatever they want to do,” Vicente Diaz, a principal security researcher with Kaspersky, told The Associated Press.