Russian security company Kaspersky Lab released a report detailing the massive hacking spree pulled-off by a hacking group based in Russia.
The report said the hacker group stole US$1 billion by penetrating at least 100 banks across 30 different countries. According to Kaspersky the group has been operating since 2013.
The group mainly used a common hacking tactic called "spear phishing" along with other methods to gain access to the target banks computer systems. After successfully integrating itself into the system, the hacker's malware gathered important personal information.
Once the hackers gained enough information, it used the stolen information to transfer money into bogus accounts. The hackers also reprogrammed ATM's to dispense money at specific time to waiting accomplices, according to Fox News.
The report was presented during a security conference held at Cancun, Mexico.
According to Kaspersky the hackers limited their theft to only about $100 million per bank to avoid early detection. Kaspersky principal security researcher Vicente Diaz said the hacking attack were unusual because the hacker group targeted the banks directly rather that attacking individual accounts, which is the usual scheme.
Kaspersky also said the attacks were focused on financial gain rather than espionage.
"In this case they are not interested in information. They're flexible and quite aggressive and use any tool they find useful for doing whatever they want to do", Diaz said.
Most of the targeted banks were based in Russia, the United States, Germany, Ukraine and China. There's also a big possibility the hackers will expand its operations to Asia, the Middle East and Africa.
In one reported case, an unnamed bank lost $7.3 million through fraudulent ATM transactions. A financial institution lost around $10 million when the hackers took advantage of an unpatched bug in its online banking platform, according to USA Today.