You'll surely enjoy the quote from the linked article:
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The method is seemingly simple, but the fact that the thieves knew to focus on this particular vulnerability marks the Citigroup attack as especially ingenious, security experts said.
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Sorry but no, this isn't ingenious - it's really the basics!!!
Of course they did, if they made it look simple then everyone would freak out (or they should, and have mass exodus away from Citi). People are used to hackers finding occasional, difficult exploits.
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The method is seemingly simple, but the fact that the thieves knew to focus on this particular vulnerability marks the Citigroup attack as especially ingenious, security experts said.
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Sorry but no, this isn't ingenious - it's really the basics!!!