What does the Conficker worm do?

Posted on 8:21 PM by Bharathvn

If you’re worried about the Conficker worm striking on April 1st, don’t be.

On April 1st the Conficker worm will simply start taking more steps to protect itself. After that date, machines infected with the “C” variant of the worm may not be able to get security updates or patches from Microsoft and from many other vendors. The creators of the worm will also start using a communications system that is more difficult for security researchers to interrupt.

The Conficker worm, sometimes called Downadup or Kido has managed to infect a large number of computers. Specifics are hard to come by, but some researchers estimate that millions of computers have been infected with this threat since January. Current users of Symantec’s Norton security products are protected. Users who lack protection are invited to download a trial version of Norton AntiVirus 2009,Norton Internet Security 2009 or Norton 360. All of these products will detect and remove this worm. Symantec has a detailed technical analysis of the threat here.

What does the Conficker worm do?

We don’t know the purpose of the Conficker worm. Today the worm has created an infrastructure that the creators of the worm can use to remotely install software on infected machines. What will that software do? We don’t know. Most likely the worm will be used to create a botnet that will be rented out to criminals who want to send SPAM, steal IDs and direct users to online scams and phishing sites.

The Conficker worm mostly spreads across networks. If it finds a vulnerable computer, it turns off the automatic backup service, deletes previous restore points, disables many security services, blocks access to a number of security web sites and opens infected machines to receive additional programs from the malware’s creator. The worm then tries to spread itself to other computers on the same network.

How does the worm infect a computer?

The Downadup worm tries to take advantage of a problem with Windows (a vulnerability) called MS08-067 to quietly install itself. Users who automatically receive updates from Microsoft are already protected from this. The worm also tries to spread by copying itself into shared folders on networks and by infecting USB devices such as memory sticks.

Who is at risk?

Users whose computers are not configured to receive patches and updates from Microsoft and who are not running an up to date antivirus product are most at risk. Users who do not have a genuine version of Windows from Microsoft are most at risk since pirated system usually cannot get Microsoft updates and patches.

What to do if you are infected

  1. Use your Norton product to identify which variant of the worm is on your computer.
  2. Follow the detailed removal instructions for the specific version of the of the worm. These can be found here:

    W32.Downadup.A writeup
    W32.Downadup.B writeup
    W32.Downadup.C writeup

Advice to Stay Safe from the Downadup Worm:

  1. Run a good security suite (we are partial to Norton Internet Security and Norton 360).
  2. Keep your computer updated with the latest patches. If you don’t know how to do this, have someone help you set your system to update itself.
  3. Don’t use “free” security scans that pop up on many web sites. All too often these are fake, using scare tactics to try to get you to purchase their “full” service. In many cases these are actually infecting you while they run. There is reason to believe that the creators of the Conficker worm are associated with some of these fake security products.
  4. Turn off the “autorun” feature that will automatically run programs found on memory sticks and other USB devices.
  5. Be smart with your passwords. This includes
  1. Change your passwords periodically
  2. Use complex passwords – no simple names or words, use special characters and numbers
  3. Using a separate, longer password for each site that has sensitive personal information or access to your bank accounts or credit cards.
  1. Use a passwords management system such as Identity Safe (included in Norton Internet Security and Norton 360) to track your passwords and to fill out forms automatically.
  2. Run Norton Internet Security, Norton AntiVirus or Norton 360. You can also try Norton Security Scan.


FAQ

Q: Am I safe if I don’t go to questionable web sites?

A: No. The Conficker worm seeks out computers on the same network. You can be in a coffee shop, an airport or in the office and the worm will quietly try to attach to your computer and run itself.

Q: How do I know if I am infected?

A: The best way to know if you are infected is to run a good antivirus product. One symptom that may indicate you are infected is finding that your computer is blocked from accessing the web sites of most security companies.

Q: Can’t I just run free antivirus software?

A: Yes, but free products often aren’t thorough or comprehensive. Worse, the internet is overflowing with fake free security scanners that actually infect your computer. Fake scanners such as “Antivirus 2008” are difficult to identify and have plagued hundreds of thousands of users around the world.