The details of more than 1.3 million credit and debit cards - most of them from India - have been put up for sale on an underground forum.
The database, which has been on the Joker's Stash carding forum since 28 October, was spotted by cybersecurity firm Group-IB.
More than 98% of the card records belong to Indian bank customers, while about one per cent come from Colombian banks.
The crooks are selling the cards for $100 each, valuing the entire database at more than $130 million.
The dump contains Track 1 and Track 2 data, which Group-IB says can be used to produce cloned cards for cash out operations.
Ilya Sachkov, CEO, Group-IB, says: "This is indeed the biggest card database encapsulated in a single file ever uploaded on underground markets at once."