Virus Encyclopedia

Welcome to the Virus Encyclopedia of Panda Security.

Sasser.A
Threat Level Damage Distribution

Is my computer infected by Sasser.A?

In order to make absolutely sure that Sasser.A has not affected your computer, you have the following options:

1. Carry out a full scan of your computer using Panda Antivirus, after checking that it is updated. If it isn't and you are a registered Panda Software client, update it by clicking here.
2. Check the computer with Panda ActiveScan, Panda Software's free, online scanner, which will quickly detect any possible viruses.

How to remove Sasser.A? 

In order to prevent your computer from being affected again by Sasser.A, protect it by applying the security patch, available through Microsoft’s website. Click here to access the web page for downloading the patch.

Note: While the security patch is not installed, your machine will present the vulnerability which Sasser.A exploits in order to affect it, and it will restart itself whenever you are connected to the Internet. Keep in mind that, in case you would reformat your computer and reinstall the Windows XP/2000 operating system, it is necessary to reapply the security patch, in order not to be affected again.

Bear in mind that computers affected by Sasser.A restart every 60 seconds. This means that there is no time to download the Microsoft patch. One way that users can get round this is by first putting the system clock back, as described below:

• When the window is displayed saying that the system will restart, double-click on the time displayed at the right bottom of the screen.
• Once the time settings window opens, put the clock back a few hours.

If, once the security patch is applied, Panda Antivirus or Panda ActiveScan detects Sasser.A during the scan, it will automatically offer you the option of deleting it. Do this by following the program's instructions.

As an extra precaution run our free utility Panda QuickRemover, which will automatically repair any damage that Sasser.A may have caused in your computer. In order to do this, follow these instructions:

If you are a Panda Software client:

• If you have a stand-alone computer or a small computer network, click here.
• If you have a large computer network protected with the antiviruses deployed through Panda Administrator, click here.

If you are not a Panda Software client:

• If you have a computer network, you should disconnect the network cable from all the servers and workstations in order to prevent them from being infected again during the disinfection process.
• Carry out the following disinfection steps in each computer in your network:
  
  1. Download the free utility Panda QuickRemover by clicking on the icon below:
  
  
  
  Save the file in any folder you want in your computer.
  
  2. Run Panda QuickRemover by double-clicking on the file and follow the instructions.
  
  Even if Panda QuickRemover indicates that it hasn't detected any active viruses, click on Continue in order to perform a full scan.
  
  3. Restart your computer.
  
  4. Carry out a full scan of your computer, including all your e-mail, using Panda Antivirus or Panda ActiveScan.

Additional notes:

• If you have Netscape Navigator installed and experience problems downloading Panda QuickRemover, follow these instructions: 1 Right-click on the icon. 2 Select the option Save link as.... 3 Select the folder in which to save it.
• After deleting this malware by following the specified steps, if your computer runs Windows Millenium, click here to find out how to eliminate it from the _Restore folder.
• After deleting this malware by following the specified steps, if your computer runs Windows XP, click here to find out how to eliminate it from the _Restore folder.

How can I protect my computer from Sasser.A? 

In order to keep your computer protected, bear the following tips in mind:

• If you have a Windows XP/2000 computer, download the security patch for the LSASS vulnerability.
• Install a good antivirus in your computer. Click here to get the Panda antivirus solution that best suits your needs.
• Keep your antivirus updated. If automatic updates are available, configure your antivirus to use them.
• Keep your permanent antivirus protection enabled at all times.

For more detailed information about how to protect your computer against viruses and other threats, click here.