After a few weeks of low activity, the infamous Waledac botnet is lighting things up once again. This time, its hook is the promise of a "fabulous" July 4 video on YouTube.Researchers at anti-virus firm ESET claim to have "reliable intelligence" that Waledac is being readied to conduct a spam campaign centering on Independence Day:

They [Waledac operators] have registered at least 18 domain names all related to the theme of video, fireworks, and Independence Day. The criminals behind Waledac are preparing to start sending spam with links to supposed videos of Independence Day fireworks which are, in reality, fresh copies of the Waledac malware family. We estimate the size of Waledac's botnet as tens of thousands of infected computers. We believe that more than 20,000 compromised computers will be used to send the malicious emails, in an effort to increase the size of the botnet.

While ESET's advisory predicted the attack would start, Web security start-up Purewire has published a note showing a sample of the attack already underway. This post has an image of the fake YouTube video, that if clicked will infect users with Waledac. Purewire points to an analysis that claims the ability for anti-virus to detect these attacks as "poor."

We covered Waledac since its purported inception. That time, it was using the Christmas holiday to spread itself.