The researchers found that the banking and financial sector was most frequently targeted by tailored malware or hacking tools for sale on the dark web, constituting about 35% of those on offer.(Photo: Bloomberg)

(Bloomberg) –Organized crime groups are selling access to the computer networks of financial firms like Bank of America Corp. and hacking tools targeting these companies, according to a British researcher who posed as a buyer on several dark web marketplaces.

While engaging criminal groups on the dark web in conversations over several months, Michael McGuire, a criminology professor at the University of Surrey, and his team discovered tools for sale to steal login credentials of many businesses, including those of Bank of America customers. They also found what sellers claimed to be the passwords and PINs of Qatar National Bank customers for sale.

Their findings, released in a research report today, offer rare insight into the workings of the dark web, the portion of the internet which requires specialized software or authorizations to access and which isn't indexed by conventional search engines.