A 40-year-old Indian-origin engineer in the US has pleaded guilty to a revenge cyber attack on the computer networks of his former employer and three ex-clients after he was fired from the job, causing them damages of over USD 130,000. Kamlesh Patel pleaded guilty yesterday in US District Court in Boston to two counts to causing damage without authorisation to Internet-connected computers and to one count of using means of identification to commit the offense. US District Court Judge Leo T Sorokin scheduled sentencing for September 28, Justice Department said. Patel worked as a senior network engineer at Northborough-based Baesis Inc, a company that offered network maintenance and security services to its clients. In October 2010, after Baesis terminated Patel, he used a colleague's network credentials to access Baesis\u2019s computer network and deleted the company's image server, a computer that stored copies of clients' network configurations. In late January 2011, Patel used his former colleague's credentials once again to access Baesis's network and the networks of three former clients. Patel used specialised software to delete data from all four companies' networks. As a result, the victim companies temporarily lost use of their networks, including Internet and e-mail access. One victim company lost access to its Internet telephone system for several weeks. Patel's victims incurred USD 137,896 in damages. He has agreed to pay this amount in restitution in connection with his plea. The charges of causing damage without authorisation to Internet-connected computers provides for a sentence of no greater than 10 years in prison, three years of supervised release and a fine of USD 250,000. The charge of using means of identification to commit a felony provides for a sentence of no greater than five years in prison, two years of supervised release and a fine of USD 250,000.