A September 2005 security breach that remained undetected until "recently" may have compromised the names, addresses and credit card details of roughly 27,000 online customers of computer memory vendor Kingston Technology Company.
The California-based company began sending letters to affected customers informing them of the incident last week.
According to a spokesman, Kingston’s IT team "detected irregularities" in the company computer systems at some unspecified point in time and – along with a team of forensic computer experts – began investigating the issues. It was not until after that probe was completed and a final report released on May 22 that Kingston could confirm the scope of the intrusion and its impact.
"After confirming what data was accessed and who was affected, Kingston had to gather the appropriate contact information and arrange for consumer protection services and materials to notify the impacted consumers," the spokesman said.
But the company did not offer details on how or when the breach was discovered and how long it waited to notify customers about the potential compromise of data. Kingston, which had $3bn (£1,46bn) in sales last year, also did not offer any explanation on the nature and scope of the breach itself or why it remained undetected for so long. The spokesman added that the breach is believed to have been perpetrated by an external attacker.
In an emailed statement, the company said it has taken "aggressive steps" to minimise any potential risk to those affected by the illegal access. The vendor said it has contracted with New York-based security consulting firm Kroll to provide services such as credit monitoring and, if needed, "identity restoration" free of charge to affected customers.
"Following the discovery of the intrusion, Kingston engaged a top computer forensics firm to conduct a thorough investigation and assist in the development of even greater levels of system security to protect against future attacks," the statement said. The company did not elaborate on what those measures were.
The note added that, for the moment at least, there is no evidence that the illegally accessed data has been misused. "Kingston has always made customer privacy a priority and deeply regrets this situation, which is the first of its kind in the nearly 20-year history of our company," it noted.