A data program used by Hillary Clinton’s campaign was hacked, an aide said Friday, as a broad pattern of cyberattacks on Democratic political organizations began to emerge.

The Clinton campaign and the Democratic Congressional Campaign Committee both were targets in cybersecurity incidents, along with the Democratic National Committee, which recently saw a trove of hacked emails released after an attack.

Nick Merrill, a Clinton spokesman, said an analytics data program used by the campaign had been accessed as part of the breach at the party’s headquarters. The program was maintained by the DNC and had been available to the Clinton campaign and other entities.

Outside cybersecurity experts have found no evidence that the campaign’s internal computer systems have been compromised, Mr. Merrill said.

The hackers were able to access the analytics program’s server for about five days, a campaign aide said. The data program was used by the Clinton campaign to conduct voter analysis, but it didn’t include Social Security numbers or credit-card information. The breach in this system couldn’t have resulted in access to the campaign’s internal emails, voicemails, computers or other internal communications and documents, according an outside cybersecurity expert, the campaign aide said.