The French software developer turned rogue trader who cost French bank Société Générale an estimated €4.9bn ($7.2bn) used co-workers' access codes to set up fraudulent transactions.
Jerome Kerviel used his colleagues' access codes and sent fraudulent email in order to create fictitious accounts to take risky positions in the derivatives market, resulting in huge losses as stock markets across Europe fell. He used his five years' experience in helping to develop the bank's trading systems to remove limits on his personal trading positions, and faked customer accounts to balance the books.
He also used hacking techniques to turn off warning systems that could have alerted his bank about anomalous trading patterns, The Daily Telegraph reports. This sounds complicated, but could have been as simple as manipulating the production of Excel spreadsheets that are used to provide trading updates to bosses, according to City experts.
A copy of Kerviel's CV found circulating on the net - which lists Microsoft Office and Microsoft Visual Basic as his only IT-related skills - supports the theory that the rogue trader carried out a low-tech hack
, Information Week adds.