The Storm botnet has spent its vacation on a recruiting trip, transforming its latest disguise from a Christmas card to a New Year's message.
Storm, one of the world's most cunning and dangerous botnets to date, has been relatively quiet this month, but a renewed effort to turn PCs into Storm zombies was detected over the weekend, according to a report from Prevx and several other security vendors. (See The World's Biggest Botnets .)
The new variants of the Trojan-bearing worm began as a message containing graphics of scantily-clad women wearing Santa-style underwear and a few lines of text promising more to users who clicked on the attached link.
As in past attacks, the bot herders released new variants of the worm every few minutes, repacking the code from server, Prevx says. This approach makes it difficult for security vendors to create a valid signature to defend against.
The problem was complicated just two days later, when Storm's operators began sending out new variants under a New Year's theme. Prevx says it saw 166 repacked versions of the worm in the first 10 hours of today.
The bot herders are also using fast-flux DNS (Domain Name System) tactics to keep the Uhavepostcard.com site operational, according to a report from Symantec. In fast flux, infected bot machines (typically home computers) serve as proxies or hosts for malicious Websites. These are constantly rotated, changing their DNS records to prevent the botnet's discovery. (See Attackers Hide in Fast Flux and On the Trail of 'Fast Flux' Botnets.)
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