Dark Reading

A telecommuter's casual link to a file-sharing network leaked personal information on more than 17,000 current and former employees at pharmaceutical giant Pfizer.

In a letter to employees dated June 1, Pfizer privacy officer Lisa Goldman states that the data was stored on a Pfizer laptop used in an employee's home.

"Due to the unauthorized installation of certain file sharing software on the laptop, files stored in the laptop containing the names, Social Security numbers, and in some instances, addresses of approximately 17,000 present and former Pfizer colleagues were exposed to one or more third parties," the letter says.

In a subsequent letter to the Attorney General of New Hampshire, Pfizer attorney Bernard Nash states that 15,700 of the employees definitely had their data accessed and copied, and another 1,250 might have lost data as well.

Pfizer did not say how it discovered the hack, nor which file sharing networks or software were involved. "Our investigation revealed that files containing names and SSN data were exposed to and, in some instances, accessed by one or more unauthorized persons over a 'peer-to-peer' network," the letter says. "[But] we were unable to determine the identity or location of those persons, or whether any particular file was opened or examined."

The company has disabled the file sharing software and is "taking steps to prevent any further dissemination of these files," the letter says. Pfizer said it has notified the Attorneys General in all of the states where employees might be affected and is also working to find out the identities of anyone who may be re-posting the files.

The data loss makes prophets of researchers at Dartmouth University, who warned of this type of file loss in a paper presented last week. The U.S. Patent and Trademark Office and security vendor Promisec also issued warnings on P2P threats last month. (See P2P's Unintended Leaks and Security Audit Reveals Threat Potential.)

The problem, according to the Dartmouth researchers, is that although most companies have outlawed the use of P2P file sharing on the corporate network, many employees install it on their remote and home computers so they can download music and videos over the Web. But this practice may open up many other files on the laptop for sharing, and many can be found using simple search functions on P2P networks.

The Pfizer employee had installed the P2P software from home, and was using it on the public Internet and not on the Pfizer corporate network, according to the company's disclosure documents.

Pfizer did not say whether or how the employee who installed the P2P software will be disciplined. All of the company's employees have been given a free connection to a credit monitoring service.

— Tim Wilson, Site Editor, Dark Reading