Dealing with Viruses

To begin scanning in Avast make sure you have:

• Updated the Avast virus definitions (refer to section 3.1 How to Update Avast)
• Configured the scanning options (refer to section 3.2 How to Configure Avast)

Step 1. Click: to begin the scan.

The virus scan may take a while (especially if you have followed the recommendations above and told Avast to perform Thorough scans). If you wish, you can leave your computer alone while Avast is working, in which case you may have to wait an hour or more for it to finish. Or, you can use your computer while Avast is scanning, in which case it will seem a bit slower than usual. Either way, you will need to have patience. In the long run, being virus-free will increase the speed and stability of your computer.

4.1 How to Remove a Virus

If Avast detects a virus either during a scan or during normal use of your computer, you will be notified immediately as follows:

Figure 14: The Avast Warning screen

Important: You have several options to choose from in this situation. The safest would be to Delete the virus. However, a virus may infect a document that you are not willing to delete (such as an important Microsoft Office document). If that happens, you may choose to Repair the file in order to remove the virus without destroying the data. There is no guarantee that a virus-infected file can be repaired, however. If you cannot repair the file, but you still do not want to delete it, you can try moving it to the Virus Chest.

4.1.1 The Virus Chest (Advanced Users)

This is a special folder on your computer that is protected by Avast. It is isolated from the rest of the operating system; the viruses held in this folder cannot do additional damage to your computer. You cannot open a file that is in the Virus Chest, but you can store it safely in the hope that Avast will be able to restore it after some future update.

Step 1. Click: to enter the Virus Chest



Figure 15: The Avast Virus Chest screen

You can perform the following actions with files in the Virus Chest:

• Add file: Add your personal files to the User files list.
• Delete file: Files are deleted irretrievably; they are not moved to the Recycle Bin.
• Restore file: The file will be moved back to its original location and removed from the Virus Chest.
• Extract file: The file is copied to the selected folder.
• Scan file: The file is scanned for viruses.
• Show file properties: The file properties are displayed; it is possible to add your comments to the file.
• Email to ALWIL Software (the makers of Avast): The selected file will be sent by e-mail to ALWIL Software. You should only use this action in special cases (if you suspect that Avast made a mistake, for example, and the file is not really infected, it might be helpful to send a copy to ALWIL).

All functions are accessible from the Virus Chest interface.

Note: Moving viruses to the Virus Chest is the most convenient way of dealing with 'false positives'. This refers to files that you think have wrongly been labelled as viruses by Avast. You can then send the 'infected' file to ALWIL software and ask them to provide a final opinion.

4.2 How to React to a Virus Outbreak

Even if a virus you have found has been repaired or deleted by Avast, it is important that you take the following steps to make sure that your computer remains virus-free:

• Physically disconnect your computer from the Internet or the local network. Or, if you have a wireless connection, disconnect from the wireless network. If possible, remove your wireless card.
• If your computer is on a network, either at work or at home, you should immediately disconnect all computers on that network from the Internet and then from the local network. All other users should stop working and help you clean up the virus infection. This may sound like an exhausting process, but it is absolutely necessary.
• Schedule a boot-time scan (see below) on all computers in the network. Write down the names of any viruses that you find and then delete them.
• Repeat the step above, running boot-time scans on all computers, until Avast no longer shows a warning. You may only have to do this once.
• Use Avast's Virus Database and an Internet search engine to research specific details about the virus and possible damage caused by the infection.

Step 1. To open the Avast Virus Database, click and choose Virus Database from the drop-down menu.

Figure 16: The Avast drop-down menu with Virus Database selected

Here you can learn details about the virus, including what steps you should take in order to prevent the infection from spreading. Remember, you can also search on the internet using the text listed in the Name column of the Avast Virus Database.

Figure 17: The Avast Information about known viruses screen

4.3 How to Perform a Boot-Time Scan

Boot-time refers to the period between turning on your computer and before the Windows Operating System starts. A boot-time scan is the most complete way to scan your computer for viruses. This is useful because some viruses hide in files that Avast cannot scan while Windows is running.

Step 1. Click: to activate the drop-down menu and select Schedule boot-time scan.

Figure 18: The Avast Schedule boot-time scan

Step 2. Click the Schedule button

You will need to restart your computer for this boot-time scan to take place. When you restart the computer, Avast will check it for viruses and then Windows will start up as normal. You cannot use your computer while a boot-time scan is taking place, but you should stay nearby so that you can respond to any viruses that are found.

Figure 19: The Avast Schedule boot-time scan

If a virus is found, you will be given a choice of repairing it, deleting it or moving it to the Virus Chest. It is recommended that you choose one of these three actions rather than choosing to Ignore the virus. Please follow the guidelines above when making your decision. If you select Delete all, Move all, or Repair all, then Avast will stop asking you questions and do the same thing for all viruses that it finds during this boot-time scan.

4.4 About the Virus Recovery Database (VRDB)

The Avast Virus Recovery Database (VRDB) adds yet another layer of virus protection. It lets you restore an infected system to an operable state. Avast's VRDB will automatically create and securely store copies of important system files. If a virus infects them in the future, Avast will try to revert to using the safe copies.

The Avast VRDB is activated by default after Avast has been installed.

Step 1. Right-click on the icon to view the different options in the VRDB as follows:

Figure 20: The Avast boot-time scan in progress in Windows XP

Step 2. Select the Generate VRDB Now option after installing and updating Avast. This will ensure that you have a recent copy of all your system files. This process will run in the background and may take several minutes to complete.