Jul.02, 2010, 4:33 PM EDT

A former IT staffer with the Bank of New York Mellon pleaded guilty Thursday to stealing sensitive information belonging to 2,000 bank employees and then using that data to steal more than US$1 million from charities.

Adeniyi Adeyemi, 27, had worked as a contract computer technician at the Bank's Manhattan headquarters, and the data he allegedly stole belonged primarily to co-workers in the bank's IT department.

He pleaded guilty to theft, money laundering and computer tampering charges in New York City Criminal Court Thursday, the New York District Attorney's Office said in a statement.

Over an eight-year period, Adeyemi stole more than $1.1 million from charities by transferring funds from the charities' bank accounts into bogus accounts he'd set up using the personal information of his former co-workers, prosecutors say. He "input the charities' banking details, including account and routing numbers, to set up wire transfers on the E*Trade and Fidelity sites from the charities' account to his dummy accounts, and withdrew the stolen funds or transferred them to a second layer of dummy accounts," the district attorney's office said in its press release.

More than a dozen charities were victimized, including Goodwill Industries of Greater New York, the Jacksonville Humane Society and the International Association of Women Judges, all of which had publicized their bank account details in order to receive donations.

Fraudsters are able to transfer money from bank accounts using a back-end system used for interbank transactions called the Automated Clearing House (ACH) network, which has been used to move tens of millions of dollars in fraudulent transactions over the past year.

Adeyemi also admitted to stealing money from his former colleagues, taking control of their online bank accounts and then wiring money to his dummy accounts, the district attorney said.

He spent the proceeds on U.S. Postal Service money orders, to pay his rent and credit cards, and to purchase goods that were then shipped to Nigeria, prosecutors said. He is scheduled to be sentenced on July 21.

Robert McMillan covers computer security and general technology breaking news for The IDG News Service. Follow Robert on Twitter at @bobmcmillan. Robert's e-mail address is robert_mcmillan@idg.com