While earlier variations of the Conficker worm prevented infected machines from accessing the servers of most antivirus companies, this new variant also blocks access to sites that offer tools for removing the worm like BitDefenders bdtools.net.

Oddly, the Conficker worm now also includes an instruction that tells the worm to remove itself on May 3 (the hackers clearly like deadlines), though after that, it will keep a port open on these machines that will allow the hackers to get back into these computers at any time.

The Big Picture: Spyware, Spambots, Pop-Ups

According to both Trend Micro and Symantec, Conficker, after downloading its update, also downloads a variant of the well-known Waledac malware. Waledac is one of the world's most active spambots.

Security researchers are still trying to understand the connection between Waledac and Conficker's new E variant (only a small number of antivirus products can currently detect this version of Waledac, by the way). Some, however, speculate that this connection could mean that Conficker was created by the same group of hackers that created Waledac and its predecessor, the infamous Storm botnet.

Business Model?

According to Kaspersky Labs' Alex Gostev, Waledac will download a rogue antivirus application onto infected machines, as well as an email-worm that can steal data and send spam. The fake antivirus software will ask users to pay $49.95 for "Spyware Protect 2009," which, of course, is anything but an antispyware product.

Protect Yourself (and others)

Of course, if your Windows machine is up to date and if you have kept your antivirus software up to date then chances are very good that you are well protected against Conficker.

If you want to learn more about Conficker and how to protect yourself, have a look at this list of resources we put together last month. If you want to see if you are infected, head over to this site from the University of Bonn.

While some news outlets are causing panic with their fear mongering, others are downplaying the upcoming event, and the net effect of course is FUD. But according to security experts, the bottom line is if you're not infected now, you don't have anything to fear come April Fools Day. If you're interested in knowing more about Conficker and how to search for and destroy it, take a look at the seven resources below.

The Last Watchdog has compiled a simple timeline to show the evolution of Conficker that begins with Chinese hackers selling a $37 malware kit in September 2008 designed to exploit a security hole in Windows, and ends with what infected PCs will do come April 1 2009.

Conficker C Analysis

The computer science laboratory at SRI International, sponsored by the National Science Foundation and the U.S. Army Research Office, has released a detailed analysis of Conficker C.

Ensure you've got the latest Microsoft patch

Microsoft recommends you manually download the Windows Malicious Software Removal Tool. Note: This is not a replacement for anti-virus software, rather an additional defense.

Disable Autorun

PC World suggests disabling Autorun so that your machine won't be automatically infected when you connect to infected removable media. A how-to can be found here. Note: This involves changing the registry file on Windows and should only be done by those confident in their abilities.

Search for and destroy Conficker with F-Secure

F-Secure has a free and easy-to-use tool to check for and remove worms; including the dreaded Conficker.

Use McAfee's Stinger which will update daily in preparation for April 1

McAfee has created a special build of its standalone cleaning tool Stinger which it will be updating daily to include any new Conficker variants.

No Download: Scan on the Web

Create a free account (registration required) with Panda Security's ActiveScan to perform an online scan of your machine.

Image Credit: Flickr: Jean et Melo