Insurance company Aetna has contacted 65,000 current and former employees whose Social Security numbers (SSNs) may have been compromised in a Web site data breach.
The job application Web site also held names, phone numbers, e-mail and mailing addresses for up to 450,000 applicants, Aetna spokeswoman Cynthia Michener said. SSNs for those people were not stored on the site, which was maintained by an external vendor.
The company found out about the breach earlier this month when people began receiving spam messages that appeared to come from Aetna and complained to the company, Michener said. The spam purported to be a response to a job inquiry and requested more personal information.
The spam campaign showed the intruders successfully harvested e-mail addresses from the Web site, although Michener said it's not clear if SSNs were also obtained.
Nonetheless, Aetna sent letters last week notifying the 65,000 people whose SSNs were on the site of the breach. The company is offering them one year of free credit monitoring, as SSNs are often used by identity thieves.
"We wanted to err on the side of caution," Michener said.
Aetna hired an IT forensics company to investigate how the Web site had been compromised. "At this point despite a thorough review, they've not been able to pinpoint the precise breach," Michener said.
Aetna posted alerts on the job site, its main Web site and its internal intranet about the spam campaign, Michener said.