 |
» |
|
|
|
|
|
|
|
|
HP and Compaq Desktop PCs - Resolving and Preventing Viruses on Your Computer
This document applies to HP and Compaq desktop computers.
This document explains differences between viruses, helps in removing viruses, and offers suggestions for preventing future viruses.
| CAUTION:
|
Never open an attachment or a link in an e-mail when you do not trust the sender. Sometimes a person intending to do harm sends an e-mail message that appears to be from a trusted source, such as Microsoft. Most trusted companies do not attach software to e-mail. If you do not trust an e-mail, research it on the Internet or contact the company or sender named in the e-mail. |
|
NOTE:
|
This document is not about spyware, adware or browser hijacking. Spyware might make the computer slow when connecting to the Internet and the computer might function as if it has a virus, but this is not discussed further in this document. For more information about spyware, adware or browser hijacking, see
About Spyware, Adware, and Browser Hijacking Software
. |
Defining viruses, worms, hoaxes, Trojans, and security vulnerabilities
There are thousands of different viruses and damaging software programs that can harm your computer or make it perform slower. Typically, these software programs are the following:
Hoax
- An e-mail that usually states that it is harming the computer, but does not actually do what it says. Some hoaxes ask the reader of the e-mail to perform a damaging process, such as deleting an important file. Most hoaxes are spread by people who do not know that the e-mail is a hoax and who are hoping to alert others to a potential virus.
- Phishing
- Methods used to try to and move people browsing the Internet to a malicious Web site. When a person visits the Web site, the Internet browser tries to read malformed code on the page and induces a security hole or the Web page itself is designed to look similar to another popular Web page (to collect credit card or other personal information).
- Security Vulnerability
- A weakness in software that allows unwanted activity inside the operating system.
Trojan
or Trojan Horse
- A software program usually created to make a computer less secure. The software usually looks similar to a useful file that a person would want to open. The payload of a Trojan is usually delivered when the file opens and usually has devastating results. Trojans are often used to create back-doors (a program that allows outside access into a secure network). Trojans are most often delivered as an e-mail attachment or through security vulnerabilities while browsing the Internet.
Virus
- A software program that copies itself into another program, a hidden space on a drive, or items that support scripts. Most viruses copy only themselves, while a minority unleash a payload - actions caused by the virus. Payloads can damage files, deliver Trojan files, corrupt hard drives, display messages, or open other files. Typically, payloads deliver when a certain condition occurs, such as when the date on the computer reaches a particular day.
A virus variant
is a virus that has been altered to take advantage of the original virus code. By doing this, the virus variant is easier to create, creating more virus versions.
Worm
- Another form of virus that finds vulnerable computers and copies itself to those systems. The most frequent methods of propagation are from e-mail distribution lists, e-mail signature scripts, and shared folders on the network. Worms might or might not have a damaging payload. The typical payload for a worm makes a computer more susceptible to other viruses and Trojans.
Instructions for resolving and preventing viruses
The steps in this section help you find, eliminate, and prevent viruses on a computer.
|
NOTE:
|
If your computer has Windows XP or Windows Vista, and you think the computer might already have a virus, you can try
Microsoft's Malicious Software Removal Tool
(in English) to find and remove most common strains. |
|
NOTE:
|
When the computer is serviced or when a system recovery has been done, the computer software is changed back to its original configuration, meaning it is set to the same condition as when the computer was first purchased. All software and driver updates that were installed on the computer, from the time it was first started, are lost. In this like-new condition, the computer is more susceptible to viruses because the added security updates have also been removed. Perform the steps in this section after the computer returns from service or after running a system recovery. |
|
NOTE:
|
To fully protect a computer from virus attacks, install and use a firewall
. Microsoft Windows 7, Vista, and XP have built-in firewalls. Many new HP and Compaq computers come with alternative Firewall software as well. Also, there are several firewall applications you can find by searching for them on the Internet. |
Step 1: Obtaining Windows Security updates
Installing the latest critical updates from Microsoft makes a computer more secure. Regularly use Windows Update to help prevent the contraction of future viruses.
For more details on the latest vulnerabilities, review the following Microsoft Web page:
Windows Security Updates
(in English). |
NOTE:
|
Even if the latest critical updates were installed a week ago, check for updates again. Check for Windows updates on a consistent basis. Microsoft regularly provides critical updates to make Windows more secure. These updates are important for protecting a computer. If you have an always-on broadband connection, set the Window Update tool to automatically check for updates daily. |
To use Windows Update, connect to the Internet and go to the
Windows Update
Web site. Agree to the terms from Microsoft and follow the directions on the pages to continue. To make sure that the computer is free of viruses, continue through the remaining steps of this document. Step 2: Checking to see if virus scanner software is installed correctly
Many HP and Compaq computers come with a trial version of antivirus software already installed, but you should check that it is set up and running correctly.
|
NOTE:
|
Your computer might have come with a complimentary 60-day subscription to Norton Internet Security. HP recommends following on-screen prompts to renew your subscription. Renewing your subscription not only helps protect your system against new threats, but can enhance Norton Internet Security with online protection that is faster, more responsive, and uses less memory |
You can quickly determine if a computer has security software installed by moving the mouse pointer along the lower right corner of the Windows Desktop, over the icons next to the clock. A small text window displays over each icon. Read the text over each icon to find the tray icon for the security software. Right-click this icon to open the security software or examine more options.
Figure 1: Tray icon for Norton Internet Security
Tray icon for Norton Internet Security If you could not find a tray icon or you are still not sure if your computer has security software, do the following, depending on which version of Windows is running on the computer:
In Windows 7, click Start
, type action center
into the Search field, and press Enter
to view the status of your security software. In Windows Vista, click Start
, type security center
into the Search field, and press Enter
to view the status of your security software. In Windows XP SP2, click Start
, click Control Panel
, and then click Security Center
to view the status of your security software.
For other versions of Windows, look through the Start menu to find security or antivirus software.
If an antivirus software program is installed, skip to Step 4
. Otherwise, continue to the next step to install security software.
Step 3: Installing antivirus software
If antivirus software is not installed, HP recommends that you install antivirus software. New viruses are created and released often, and without antivirus software, the files and folders on the computer are at risk.
Computers with Windows 7 and Windows Vista come with Windows Defender. Most HP and Compaq computers come with free trial versions of antivirus software. These trial versions are usually limited versions that can be kept up-to-date for a specific period. After the period expires, your computer becomes more vulnerable to new viruses and security threats. Upgrade or refresh the subscription to keep virus definitions current and continue protecting your computer.
For example, Norton Internet Security provide a HP and Compaq computers with a free 60-day subscription to its virus protection service. You can download the latest virus information lists, called definitions, from Live update for 60 days. After that time, you can buy a subscription renewal from Symantec to safeguard the computer against the latest threats.
|
NOTE:
|
If you have antivirus software installed, but want to install different antivirus software, make sure to remove the old antivirus software before installing new software. Doing so might avoid software conflict problems. |
If you do not have any virus scanning software installed, you can buy and use professionally developed products, such as the following products by Symantec:
Step 4: Updating antivirus software definitions
Because new viruses are created and released often, regularly update the virus definition files for the antivirus software. A virus definition file is a list of known viruses that the antivirus software uses to find and eliminate viruses. Do the following to update the virus definitions:
Open the antivirus software.
Click buttons or menu items that read, update
or live update
.
An update window opens. If the window does not open or if you cannot find the update feature, go to the antivirus software manufacturer Web site for more information. For a list of antivirus software support Web sites, see the Related support
section.
Step 5: Scanning for viruses
After updating the virus definition files for the antivirus software, scan for viruses. Because each antivirus software has its own way of scanning for viruses, see the software manufacturer's Web site or help files if you need help scanning. Usually, you can scan for viruses by opening the antivirus software and clicking a scan button. For a list of antivirus software support Web sites, see the Related support
section. If you computer has Windows 7 or Windows Vista, you can scan for malicious software using Windows Defender. To do so, click Start
, and type defender
into the Search box, and then click Windows Defender
. Click Scan
. Figure 2: Opening Windows Defender
Opening Windows Defender through the Search box If a virus is found, the virus might have already damaged or destroyed some files on the computer. The antivirus software might or might not be able to repair the damage. If the software cannot repair the damage, the computer might need to be fully recovered. See Related support
for information on performing a system recovery. |
NOTE:
|
If a virus was found and removed, open System Restore and delete any dates when the virus was active. This prevents the computer from accidentally becoming reinfected. See Related support
for information on using Microsoft System Restore. |
Windows vulnerabilities and security threats known by Microsoft
To keep aware of the latest Windows threats and vulnerabilities, see the
Latest security bulletins
from Microsoft (in English). Specific virus and security vulnerability information
This section of the document contains links to specific information on the latest viruses and security vulnerabilities.
Conficker worm
The Conficker worm is a computer worm virus that can infect your computer and automatically spread itself to other computers on a network through file sharing (Windows Server service), and removable drives, such as USB thumb drives. It disables several important system services and security products. For more information and removal instructions, see the following Microsoft Web page:
Protect yourself from the Conficker computer worm
. Security Update for Microsoft Internet Explorer (960714)
A security vulnerability exists in certain versions of Internet Explorer. Microsoft released security bulletin
MS08-078
on December 17, 2008 to notify users of Internet Explorer. If you use Windows Update to always obtain the latest critical software updates, you are likely not to be affected by the vulnerability. If you would like to know more or to download the updates from Microsoft, see
MS08-078: Security update for Internet Explorer
(in English). Trojan.Peacomm
Trojan.Peacomm is not a virus. It is a software program that is attached to malicious e-mails. If opened, Trojan.Peacomm remains open and silently allows other programs to attack the computer. One of the more popular e-mails it is attached to starts with the subject line "X missile shot down over X country." Never open attachments to e-mail messages unless you are expecting the message and then, only after the attachment is scanned.
For more information and removal instructions, see the Symantec Web page on
Trojan.Peacomm
(in English). Blaster and Welchia worms
Even though fixes for the "Blaster" worm-virus and variants such as "Welchia" are available, these viruses still affect many computers. Click the link below for specific information on preventing and resolving these viruses:
Novarg worm (also called MyDoom or MiMail.R)
The Novarg or MyDoom worm arrives in an e-mail as a seemingly harmless file attachment. The e-mail might appear to have come from a friend because this worm uses its host's e-mail distribution list. The body text in the e-mail might state that the original e-mail has been translated into a plain-text file for delivery. The message might be different, but here are a few of the more common versions:
To prevent this worm-virus from infecting your computer, do not open the attachment and follow the steps in this document to remove viruses.
Sasser worms and variants
Sasser worms take advantage of a security vulnerability in Windows XP, similar to the Blaster worm-virus. The computer usually automatically shuts itself down with an error message about NT AUTHORITY\SYSTEM or LSA Shell (Export Version). Click the link below for specific information on preventing and resolving these viruses:
For more information and removal instructions, see the Symantec Web page on
W32.Sasser.Worm
(in English). Related support
Security software support sites (not HP)
HP and Compaq related support
|
NOTE:
|
One or more of the links above will take you outside the Hewlett-Packard Web site. HP does not control and is not responsible for information outside the HP Web site. |
|
|
Printable version
