United Parcel Service has discovered a computer breach at 51 stores, making Big Brown the latest retailer to lose customer data.
UPS said that the hacking had escaped detection at stores in 24 states, or around 1% of its locations. At most stores, the malware attack occurred after March 26, and was eliminated by August 11.
No fraud has yet been discovered, UPS said, but customer names, postal addresses, email addresses and payment card information were compromised.
Tim Davis, president of The UPS Store, apologized in a statement for any anxiety the theft may have caused customers. He said the company had deployed "extensive resources to quickly address and eliminate this issue."
Each UPS Store is franchised and runs separate computer systems, which may have helped limit the extent of the attack. UPS said the bug was not found at any of its other businesses.
The UPS breach is the latest in a long string of incidents in which hackers have made off with retail consumer data.
Just last week, Albertson's and SuperValu announced that hackers broke into their credit and debit card payment networks. Target has been hit, along with Adobe, Snapchat, Michaels, Neiman Marcus, AOL and eBay.
All in all, a CNNMoney analysis found that half of all American adults were hacked in a recent 12-month period.