While filtering methods for spam are now quite effective, a new breed of spammers has evolved and their spam evades many filters. It is time to target the next great spam problem; “snowshoe” spam.
Like a snowshoe spreads the load of a traveller across a wide area of snow, snowshoe spamming is a technique used by spammers to spread spam output across many IPs and domains, in order to dilute reputation metrics and evade filters.
Snowshoers use many fictitious business names, fake names and identities, and frequently changing postal dropboxes and voicemail drops. Conversely, legitimate mailers try hard to build brand reputation based on a real business address, a known domain and a small permanent range of sending IPs. Snowshoers often use anonymised or unidentifiable whois records, whereas legitimate senders are proud to provide their bona-fide identity.
As one of our spam filtering ‘layers’ we use the Spamhaus Project and we are using their recently introduced Spamhaus CSS – A dedicated Snowshoe component of the Spamhaus Block List.
