Red Condor Blocking 'Snowshoe' Spammers Without RBLs

Company developed proactive anti-spam technology

November 25, 2009

3 Min Read


Rohnert Park, Calif. " November 23, 2009 " Among the more common types of spam today is what has been labeled as "Snowshoe" spam, which references a spamming technique of spreading spam output across many static ranges of IP addresses and domains. As the trend has continually grown over the past several months, several email security providers have started to use publicly available Real-time Blacklists (RBLs) to block the campaigns. Red Condor reported today that it is protecting its customers and blocking the spam without using the RBLs. The company detected Snowshoe spam in late 2007, and at that time, developed an IP analyzer that helps establish filtering rules far in advance of Snowshoe spam campaigns.

While most anti-spam efforts are reactionary, Red Condor's IP analyzer proactively seeks out Snowshoe spammer IP addresses. The active technology identifies spam sources by spidering out from known spammer locations to find additional sources which may have yet to send spam.

"When our email security experts recognized this emerging threat, we were able to quickly develop the technique and rules that have protected our customers ever since, some as far back as 18 months ago," said Dr. Thomas Steding, president and CEO of Red Condor. "While our customers don't need an RBL to block Snowshoe spam, the real advantage of using a Red Condor MAG network appliance or our Hosted Service, is that these rule updates are made automatically and seamlessly to our system. Most of our customers don't care about spammers' techniques, they simply want an easy-to-use solution that stops spam and eliminates false positives; two things Red Condor does very well."

Spammers that distribute spam using the Snowshoe technique use several small IP ranges from different ISPs, and use what appear to be multiple, legitimate domains. Detecting Snowshoe spam has been difficult for most anti-spam engines because the bulk email messages are often sent through each IP address in small batches and from what appear to be legitimate, uncompromised IP addresses. In addition, the spam attacks are scattered, continuing for months then stopping, and continuing at full volume at a later date. The technique not only fools the volume-based anti-spam filters, it also handicaps the reputation metrics of most anti-spam engines.

Currently, Snowshoe spam accounts for 10% of all spam that hits Red Condor's anti-spam filters.

About Red Condor

Red Condor is revolutionizing spam fighting with its next generation technology. Red Condor's highly accurate email filter, hybrid architecture Vx Technology, and fully managed appliances lead to a dramatic reduction in the cost of owning a premium spam filter. With solutions for small businesses, as well as ISPs with millions of email inboxes, Red Condor has a cost-effective, timesaving solution that is rapidly gaining market share. The system's design has built-in zero tolerance for lost email, and a near zero false positive rate while achieving long-term spam block rates greater than 99%. Red Condor Archive is a secure message archiving service with lifetime retention and unlimited storage. The company's next-generation technology is backed by a 24x7 customer care center staffed by email security experts at Red Condor's headquarters. For more information, visit

Keep up with the latest cybersecurity threats, newly discovered vulnerabilities, data breach information, and emerging trends. Delivered daily or weekly right to your email inbox.

You May Also Like

More Insights