Visa acknowledged this week that computer crackers broke into several servers in its global network last July and stole information. The company said that in December, it received a phone call and an e-mail demanding money in exchange for the data.
The San Francisco company said no credit-card numbers or consumer information was compromised and that only outdated marketing material was involved.
Kristina Scott, a spokeswoman for Visa, said the company took steps in July to seal off vulnerable servers in the U.K. and notified authorities about the extortion demands, which may have come from an organized group of computer crackers. She said both Scotland Yard and the FBI are investigating the incidents and charges may be filed soon.
Scott said the company took other security steps after the break-in, including installing additional intrusion-detection systems, and analysed millions of lines of system logs to try to understand how the crackers gained access. She said Visa also advised its operations centres to reset all account passwords possibly affected and brought in an outside security firm to conduct a network threat assessment.