The world’s largest spam operation has been exposed, and along with it, a massive database of email addresses. More than 1.37 billion email addresses, names, addresses, and IP addresses were in the database, which was exposed as a result of an error made during a backup. The company behind the operation is the email marketing firm River City Media – A legitimate email marketing company that uses some decidedly shady email marketing practices.

So how large is the world’s largest spam operation? According to MacKeeper researchers, the company behind the massive spamming campaigns were sending up to one billion spam email messages every day. However, due to the leak, life is likely to get a lot tougher for the email marketing firm. Its entire infrastructure has now been added to the spamming blacklist maintained by Spamhaus: The world leader in providing up to date threat intelligence on email spam and related spamming activity.

So how does a database from the world’s largest spam operation get released on the Internet? Faulty backups! The company failed to configure their Rsync backups correctly, resulting in those backups being available online without any need for a password. The database was discovered by MacKeeper security researcher Chris Vickery.

The revelation that such a large database had been obtained was huge news. In fact, it even drew a response from the Indian government, which felt it necessary to explain that it was not the source of the leak. The Indian government’s federal ID system is one of a very small number of databases that contain that number of records.

The number of records in the database is so large that almost everyone that uses email would either be on the list or would know someone that is.

How does a company amass so many email addresses? According to Vickery, there are various methods used, although he said “credit checks, education opportunities, and sweepstakes,” are typically used to obtain the email addresses, as are legitimate marketing campaigns from major brands. Users divulge their email addresses during these campaigns in order to receive a free gift, special offer, or an online service. Hidden away in the terms and conditions, which few people read, is confirmation that the information collected will be shared with marketing partners. Those marketing partners then share addresses with their partners, and their partners’ partners, and so on. Before long, the email addresses will be made available to a great deal of spammers.

When spammers use those addresses, there is a high probability that the domains used for sending the marketing messages will be blocked. To get around this, companies such as RCM use warm up accounts to send out their campaigns.

New campaigns will be sent to the warm up accounts, and provided they do not generate complaints, the sender of the emails will be marked as a good sender. With a good reputation, the spammers will be able to scale up their operation and send out billions of messages. If at any point messages start to be rejected or complaints start to be received, the domain is dropped and the process starts again. That way, RCM is able to bypass spam filtering controls and continue to send messages.

A detailed insight into the world’s largest spam operation and the techniqus used to send spam messages has been published by CSO Online, which worked with Vickery, MacKeeper, and Spamhaus following the discovery of the huge database.