Have you checked your credit score recently? Probably not.

Half of U.S. adults in a new survey said they have not looked at their credit report or credit score since a huge data breach last year at credit scoring company Equifax.

The tally for the number of U.S. consumers affected has now reached about 147.9 million following news on Thursday that an additional 2.4 million individuals were affected.

Yet most people still have not taken steps to find out whether their information is at risk.

CreditCards.com's latest study found that 18 percent of the 1,164 adults surveyed have never checked their credit report or credit score.

"If the announcement of something that significant won't get people to act, then it raises the question of what will," said Matt Schulz, senior industry analyst at CreditCards.com. "I think people just feel that they have more pressing things to do."

About 3 in 10 survey respondents who had heard "a lot" about the breach still hadn't checked their credit in the past six months.

Millennials were most likely not to have heard about the breach — 26 percent. Yet at the same time, millennials checked both their credit score and report in the last six months at a higher rate — 34 percent — than any other generation.