Washington ? Details emerged Thursday behind the break-in of Republican vice presidential candidate Sarah Palin’s e-mail account, including a first-hand account suggesting it was vulnerable because a hacker was able to impersonate her online to obtain her password.

The hacker guessed that Alaska’s governor had met her husband in high school, and knew Palin’s date of birth and home ZIP code. Using those details, the hacker tricked Yahoo Inc.’s service into assigning a new password, “popcorn,” for Palin’s e-mail account, according to a chronology of the crime published on the Web site where the hacking was first revealed.

The FBI and Secret Service launched a formal investigation Wednesday. Yahoo declined to comment Thursday on details of the investigation, citing Palin’s privacy and the sensitivity of such investigations.

The person who claimed responsibility for the break-in did not respond Thursday to an e-mail inquiry from The Associated Press.

“i am the lurker who did it, and i would like to tell the story,” the person wrote in the account, which circulated on the Internet. What started as a prank was cut short because of panic over the possibility the FBI might investigate, the hacker wrote.

Investigators were waiting to speak with Gabriel Ramuglia of Athens, Ga., who operates an Internet anonymity service used by the hacker. Ramuglia told the AP on Thursday he was reviewing his own logs and promised to turn over any helpful information to authorities because the hacker violated rules against using the anonymity service for illegal activities.

“If you’re doing something illegal and causing me issues by doing this, I’m willing to cooperate,” Ramuglia said. “Obviously this is the most high profile situation I’ve dealt with.”

The break-in of Palin’s private account is especially significant because Palin sometimes uses nongovernment e-mail to conduct state business. Previously disclosed e-mails indicate her administration embraced Yahoo accounts as an alternative to government e-mail, which could possibly be released to the public under Alaska’s Open Records Act.

At the time, critics of Palin’s administration were poring over official e-mails they had obtained from the governor’s office looking for evidence of improper political activity.