Last-minute Conficker survival guide/Worm

April 1 -- is D-Day for Conficker, as whatever nasty payload it's packing is currently set to activate. What happens come midnight is a mystery: Will it turn the millions of infected computers into spam-sending zombie robots? Or will it start capturing everything you type -- passwords, credit card numbers, etc. -- and send that information back to its masters?

No one knows, but we'll probably find out soon.

Or not. As Slate notes, Conficker is scheduled to go "live" on April 1, but whoever's controlling it could choose not to wreak havoc but instead do absolutely nothing, waiting for a time when there's less heat. They can do this because the way Conficker is designed is extremely clever: Rather than containing a list of specific, static instructions, Conficker reaches out to the web to receive updated marching orders via a huge list of websites it creates. Conficker.C -- the latest bad boy -- will start checking 50,000 different semi-randomly-generated sites a day looking for instructions, so there's no way to shut down all of them. If just one of those sites goes live with legitimate instructions, Conficker keeps on trucking.

Conficker's a nasty little worm that takes serious efforts to bypass your security defenses, but you aren't without some tools in your arsenal to protect yourself.

Your first step should be the tools you already have: Windows Update, to make sure your computer is fully patched, and your current antivirus software, to make sure anything that slips through the cracks is caught.

But if Conficker's already on your machine, it may bypass certain subsystems and updating Windows and your antivirus at this point may not work. If you are worried about anything being amiss -- try booting into Safe Mode, which Conficker prevents, to check -- you should run a specialized tool to get rid of Conficker.

Microsoft offers a web-based scanner (note that some users have reported it crashed their machines; I had no trouble with it), so you might try one of these downloadable options instead: Symantec's Conficker (aka Downadup) tool, Trend Micro's Cleanup Engine, or Malwarebytes. Conficker may prevent your machine from accessing any of these websites, so you may have to download these tools from a known non-infected computer if you need them. Follow the instructions given on each site to run them successfully. (Also note: None of these tools should harm your computer if you don't have Conficker.)

As a final safety note, all users -- whether they're worried about an infection or know for sure they're clean -- are also wise to make a full data backup today.

What won't work? Turning your PC off tonight and back on on April 2 will not protect you from the worm (sorry to the dozens of people who wrote me asking if this would do the trick). Temporarily disconnecting your computer from the web won't help if the malware is already on your machine -- it will simply activate once you connect again. Changing the date on your PC will likely have no helpful effect, either. And yes, Macs are immune this time out. Follow the above instructions to detect and remove the worm.

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A computer worm is a self-replicating computer program. It uses a network to send copies of itself to other nodes (computers on the network) and it may do so without any user intervention. Unlike a virus, it does not need to attach itself to an existing program. Worms almost always cause at least some harm to the network, if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer.

Backdoors can be exploited by other malware, including worms. Examples include Doomjuice, which spreads better using the backdoor opened by Mydoom, and at least one instance of malware taking advantage of the rootkit and backdoor installed by the Sony/BMG DRM software utilized by millions of music CDs prior to late 2005.

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Reference :Yahoo!

Wikipedia

Clock ticking on worm attack code

The worm can also spread via USB flash drives.

Experts are warning that hackers have yet to activate the payload of the Conficker virus.

The worm is spreading through low security networks, memory sticks, and PCs without current security updates.

The malicious program - also known as Downadup or Kido - was first discovered in October 2008.

Although the spread of the worm appears to be levelling off, there are fears someone could easily take control of any and all of the 9.5m infected PCs.

Speaking to the BBC, F-Secure's chief research officer, Mikko Hypponen, said there was still a real risk to users.

"Total infections appear to be peaking. That said, a full count is hard, because we also don't know how many machines are being cleaned. But we estimate there are still more than 9m infected PCs world wide.

"It is scary thinking about how much control they [a hacker] could have over all these computers. They would have access to millions of machines with full administrator rights.

"But they haven't done that yet, maybe they're scared. That's good news. But there is also the scenario that someone else figures out how to activate this worm. That is a worrying prospect."

Experts say users should have up-to-date anti-virus software and install Microsoft's MS08-067 patch. The patch is known as KB958644.

Even having the Windows patch won't keep you safe Graham Cluley Sophos

Speaking to the BBC, Graham Cluley, senior technology consultant with anti-virus firm Sophos, said the outbreak was of a scale they had not seen for some time.

"Microsoft did a good job of updating people's home computers, but the virus continues to infect business who have ignored the patch update.

"A shortage of IT staff during the holiday break didn't help and rolling out a patch over a large number of computers isn't easy.

"What's more, if your users are using weak passwords - 12345, QWERTY, etc - then the virus can crack them in short order," he added.

"But as the virus can be spread with USB memory sticks, even having the Windows patch won't keep you safe. You need anti-virus software for that."

Method

According to Microsoft, the worm works by searching for a Windows executable file called "services.exe" and then becomes part of that code.

It then copies itself into the Windows system folder as a random file of a type known as a "dll". It gives itself a 5-8 character name, such as piftoc.dll, and then modifies the Registry, which lists key Windows settings, to run the infected dll file as a service.

Once the worm is up and running, it creates an HTTP server, resets a machine's System Restore point (making it far harder to recover the infected system) and then downloads files from the hacker's web site.

Most malware uses one of a handful of sites to download files from, making them fairly easy to locate, target, and shut down.

But Conficker does things differently.

Right now, we're seeing hundreds of thousands of [infected] unique IP addresses Toni Koivunen, F-Secure

Anti-virus firm F-Secure says that the worm uses a complicated algorithm to generate hundreds of different domain names every day, such as mphtfrxs.net, imctaef.cc, and hcweu.org. Only one of these will actually be the site used to download the hackers' files. On the face of it, tracing this one site is almost impossible.

Variant

Speaking to the BBC, Kaspersky Lab's security analyst Eddy Willems said that a new strain of the worm was complicating matters.

"There was a new variant released less than two weeks ago and that's the one causing most of the problems," said Mr Willems

"The replication methods are quite good. It's using multiple mechanisms, including USB sticks, so if someone got an infection from one company and then takes his USB stick to another firm, it could infect that network too. It also downloads lots of content and creating new variants though this mechanism.

"Of course, the real problem is that people haven't patched their software," he added.

Microsoft says that the malware has infected computers in many different parts of the world, with machines in China, Brazil, Russia, and India having the highest number of victims.