Posted by Virus Bulletin on Nov 27, 2012
Spamhaus and SURBL results re-evaluated.
The most recent VBSpam results incorrectly stated that SURBL failed to detect a blacklisted URL in any of the emails in the Wombat feed of phishing emails; the performance of Spamhaus on the feed was also affected.
We have since discovered that a technical glitch on our side meant that none of the domains found in the emails in the Wombat feed were scanned against the SURBL domain-based blacklist, which consequently was reported not to have 'blocked' any of the emails in this feed. While it is impossible to get accurate results from checking the domains several weeks after the emails were sent, we have reason to assume that a significant portion of the emails in this feed contained at least one blacklisted domain.
The same glitch affected another participating domain-based blacklist, the Spamhaus DBL, whose performance contributes to the Spamhaus ZEN+DBL results. Thus, the performance of this solution on the Wombat feed was in fact better than the 47% catch rate reported.
The issues did not affect the performance of either blacklist on other feeds in the test, nor did it affect any of the other participating products. We offer our apologies to both SURBL and Spamhaus.
Posted on 27 November 2012 by Martijn Grooten