Apr 4, 2011 06:56 GMT  ·  By

The recently disclosed security breach at Epsilon Data Management, a big email marketing solutions provider, affects the customers of many large companies.

Last week, retail supermarket chain Kroger warned its customers that their email addresses were exposed as a result of a security breach at Epsilon.

But it seems that Kroger is not alone in this, as similar warning letters have begun popping up from numerous other top companies activating in different sectors.

According to reports, the affected firms include U.S. Bank, JP Morgan Chase, Capital One, Brookstone, McKinsey Quarterly, New York & Co, the Home Shopping Network, TiVo, City Market, Dillons, Jay C, Food 4 Less, Fred Meyer, Fry’s, King Soopers, Marriott Rewards, QFC, Ralphs, Ritz Carlton, Smith Brands and Walgreens.

The list is probably more extensive than this, considering that Epsilon is one of the largest email marketing providers in US, even larger than Silverpop, a company that got compromised last year in a similar manner.

The Silverpop breach led to the customer email lists of over one hundred companies to be stolen, including those of McDonald's, Walgreens, Honda Motors or deviantART.

It's interesting that Walgreens appears as a victim in both cases. It's not clear whether the company used both providers or if it switched from Silverpop to Epsilon only to be victimized again.

It's worth noting that following the Silverpop breach, Walgreens' customers were targeted in a mass phishing attack. Customers of Play.com, a major UK online retailer of video games, books and DVDs, received infected emails because of the same compromise.

The affected companies are informing customers to expect more spam than usual, but what they don't say is that spam takes a lot of forms, some more malicious than others.

Users are advised to always exercise caution when dealing with emails carrying attachments or links. Running a capable and up-to-date antivirus solution is also critically important.