WASHINGTON — Hackers on Thursday posted hundreds of emails from a young Democratic operative that contained documents detailing the minute-by-minute schedules and precise movements of the vice president, the first lady and Hillary Clinton during recent campaign fund-raisers and official political events.
The emails included names and cellphone numbers of numerous Secret Service agents, spreadsheets with the names and Social Security numbers of campaign donors, and PowerPoint presentations showing step-by-step directions for where officials like Vice President Joseph R. Biden Jr. should walk when they arrived at events.
The hackers who posted the emails also distributed what they claimed was a scanned image of the information page from Michelle Obama’s passport, though the authenticity of the image could not be verified.
The emails were stolen from the personal Gmail account of the Democratic operative, Ian Mellul. They reveal how widely White House officials, Clinton campaign operatives and Secret Service agents have exchanged detailed and sensitive information with people using personal email accounts.
There is no indication that Mr. Mellul, who was in effect working as a freelancer when the White House or the Clinton campaign needed help, did anything wrong, and government officials declined to talk about the use of the private account.
About a year and a half’s worth of emails from Mr. Mellul’s account were posted late Wednesday by the website DCLeaks.com, which earlier this month released a batch of emails from the personal account of Colin L. Powell, the former secretary of state, in which he voiced his scorn for Donald J. Trump, the Republican presidential nominee, and his personal peeves with Mrs. Clinton, his Democratic opponent.
The newly released emails do not provide specific security details, but they do reveal the types of movements that top political officials make at such events. If emails were hacked before an event, that could present a more serious security issue.
One document instructed Mr. Biden to walk up four steps at a loading dock in Cleveland before climbing 26 steps to a holding room. Another used blue arrows to show the route Mrs. Clinton should walk through a donor’s house in Houston. Both documents included close-up pictures of the event locations.
Mr. Mellul, who volunteered to work as an advance staff member for the White House and the Clinton campaign as he finished his undergraduate education at George Washington University in Washington, declined to comment. “I’ve got to hang up,” he said Thursday when reached on his cellphone.
Cathy L. Milhoan, the director of communications for the Secret Service, said the agency was “aware of the alleged email hacking of a White House staffer.
“Obviously the Secret Service is concerned any time unauthorized information that might pertain to one of the individuals we protect, or our operations, is allegedly disclosed,” she added.
An F.B.I. spokesman said the bureau was looking into the hacking. Josh Earnest, the White House press secretary, said that officials took “any reports about a cyberbreach seriously” and that the episode was “something we are taking a close look at.”
DCLeaks.com is a relatively new website that has posted documents taken from the accounts of prominent figures like Gen. Philip M. Breedlove, the former commander of NATO forces in Europe, and George Soros, a wealthy backer of liberal causes. On the site, its creators describe themselves as American “hacktivists” who aim to “publish a large amount of emails from top-ranking officials and their influence agents all over the world.”
Mr. Mellul hardly fits either description. His low-level job ranks just above that of an intern.
The emails from his account document the often mundane process that White House or campaign staff members go through to prepare for an event, including setting up stages, organizing photo lines, arranging for lecterns and coordinating with the Secret Service about getting clearances for all of the people the politician will encounter along the way.
One email contained a spreadsheet with the names and Social Security numbers of almost 100 people scheduled to attend a Houston fund-raiser for Mrs. Clinton. In another exchange, a Secret Service agent discussed how many official “pins” would be provided for hotel staff members to have access to an event. After Mr. Mellul said the hotel had requested 50 Secret Service pins, the agent wrote, “Yikes.”
Several of the emails contain what is referred to as a “movement document” or a “site diagram” involving the vice president, the first lady or Mrs. Clinton. Those emails were often sent to a large number of people, including Mr. Mellul. In other cases, Mr. Mellul emailed copies of the documents to other campaign or government officials, including Secret Service officials.
“Good morning all,” Mr. Mellul wrote on May 20, the day of a Hillary for America fund-raiser. “Please find the attached site diagram for Houston’s H.F.A. finance event this evening. Please let us know if you have any questions or concerns. Ian.”
The emails begin in February 2015, when Mr. Mellul was in the honors program and studying political science. In the messages, Mr. Mellul comes across as a conscientious and courteous young man whose friends would email him for help with their school essays and résumés.
After high school, he jumped into the intern circuit that feeds into entry level jobs in Washington. In 2014, he received a coveted internship at the White House and later parlayed the connections he had made as an intern into low-level freelance work for the White House.
His tryout, it appears, was helping Mrs. Obama’s team at a lunch for congressional spouses on April 15, 2015.
In an email two days before the event, Lindsay Drewel, a Washington public relations executive, wrote to Anthony R. Bernal, the deputy chief of staff for Jill Biden, the vice president’s wife, that if Mr. Mellul “can survive that crazy event (which we know he will) he’ll be ready to go! Haha.”
After the event, Mr. Mellul even included a Secret Service agent in his round of emails thanking those with whom he had worked. And the day after the lunch, the first lady’s office reached out again to see if he could help with an event in Virginia.
Mr. Mellul was excited, and in an email to a friend later that day, he noted that he had been told “it takes a few good trips/events before they really trust you.”
On April 20, 2015, five days after his first job with Mrs. Obama’s team at the congressional lunch, Mr. Mellul described himself as “on the advance team” for the first lady in an email to his professor saying he might miss class because of an event.