Zafi Slows, But Experts Urge Vigilance

The Zafi.d worm seems to have done its worst, security experts said Friday, but they urged users to remain on guard through the holidays for more seasonal shenanigans.

U.K.-based security vendor Sophos, which earlier this week claimed that Zafi.d's traffic accounted for 1 in every 10 messages worldwide said Friday that the worm had fallen off to just 1 in every 30 e-mails over the past 24 hours.

Even so, Zafi.d still accounts for over half of all virus reports, noted Sophos' senior technology consultant, Graham Cluley, in a statement, and said the danger's not all done.

"Even though the number of infected e-mails is reducing, we wouldn't be surprised to see Zafi.d spreading for months to come," said Cluley. "It seems there will always be computers which are poorly defended against threats, and they'll continue to spread viruses to the rest of us."

Cluley also warned users to watch for more holiday-slanted e-mails that may contain malicious code. "There's been a long history of worms which have taken advantage of the Christmas and New Year celebrations. Users must not let down their guard. If the holiday season makes them blind to security risks, hackers and virus writers will pounce," he said.

The advice may be too late for some. Several more worms, albeit much less prevalent on the Internet than Zafi, used the disguise of Christmas cheer to slip past users. Atak.i and Atak.j, which have been rated as low-level threats by anti-virus firms, made it into the wild Wednesday and Friday, respectively. Both pose as Christmas greetings from friends.