Investigators last week seized computers and other evidence from several individuals as part of a nationwide probe of the LexisNexis breach, in which the hackers gained access to 310,000 personal records.
The FBI said it is investigating whether the suspects used email pretending to contain child pornography to trick people into downloading software capable of capturing passwords needed to infiltrate LexisNexis' computers.
One of the hackers posed as a T-Mobile supervisor to get another employee to reveal a password into its network to get Hilton's cellphone data, FBI officials said. Later, conspiring hackers exploited a software flaw in the system.
Earlier this year, several websites published topless Hilton photos, private notes and phone numbers of her celebrity friends.
So far three people have been served search warrants in California, Minnesota and North Carolina, according to FBI spokesman Paul Bresson, who noted that his agency is working in concert with the Secret Service over the break-ins.
According to the FBI, the LexisNexis breach was set in motion by a blast of spam that included a message urging recipients to open an attached file to view child pornography. The attachments had nothing to do with child porn but the files contained a program that allowed the hackers to record anything a recipient typed on the surfer’s computer keyboard.
A police officer in Florida was among those who opened the infected email message, according to a report in the Washington Post. Not long after his computer was infected with the keystroke-capturing program, the officer logged on to his department's account at Accurint, a LexisNexis service provided by Florida-based subsidiary Seisint Inc., which sells access to consumer data. Other police officers' login information may have been similarly stolen.
The hackers apparently then created a series of sub-accounts using the police department's name and billing information, the Post said.
Over several days, the group looked up thousands of names in the database, including friends and celebrities. The law enforcement source said members of the group eventually began selling Social Security numbers and other sensitive consumer information to a ring of identity thieves in California.
