Blue Security's Do Not Intrude Registry is a list of email addresses offered to spammers for cleaning their lists. The Blue Security list, which is available free of charge, contains addresses of its members who don't wish to receive spam. It's in a hashed format, so that spammers can't extract the actual addresses.
Naturally, there are some spammers who take a dim view of organizations that try to limit the number of mailboxes they can pollute. It now appears that spammers are passing around a list of names that purports to be this secret registry. Not only that, but levels of spam received by members of the Blue Security list have roughly doubled since May 1.
So how can this be?
We've seen the spammers' list. It's not as it seems -- it doesn't include spamtraps and other special addresses or wildcard domain entries that we know to be in there. What's happened is that a spammer has taken his list and "cleaned" it against the Blue Security list. He then compared the original list with the cleaned list to figure out which addresses were removed. He then bragged to his spammer buddies that he's "cracked" the Blue Security list.
It had to happen. We're amazed it's taken so long.
This blog post from Blue Security's Eran Aloni gives more details, and this thread discusses the situation further.
This isn't a disaster for Blue Security -- people won't get spam from these spammers unless they're already getting spam from them.
... Richi Jennings