Data shows Home Depot breach could be largest ever

Company is still investigating 'unusual activity' that may affect almost every store in U.S.

It looks like Home Depot may have earned the dubious distinction of being responsible for the biggest compromise ever involving credit and debit card data.

Security blogger Brian Krebs, who first reported the data breach Tuesday, updated his report today with new information gathered from the cyber underground. According to Krebs, the data strongly suggests that a breach occurred at nearly all of Home Depot's 2,200 stores in the U.S.

Krebs based his conclusion on a review of stolen credit and debit card data posted on an online store that sells such information. The site lists each card, along with the city, state and ZIP code of the card owner, as well as the store code where the data was stolen.

Copyright © 2014 IDG Communications, Inc.