Malware or malicious software was designed by so-called hackers to obtain confidential information and to damage or gain access to a computer system in order to steal information or money. You may have noticed that your computer is running slowly, that your web browser's default start page has been changed, that you have unexpected toolbars, or that there are many windows that suddenly open (pop-ups). Even if you have an antivirus program installed, your PC may be infected with a virus or malware. Follow the steps below to check your PC and remove the malware.
Steps
Part 1 of 4: Knowing the Different Types of Malware
Step 1. Learn that viruses, Trojans, worms, spyware, and bots are all malware that can harm your system
- A Trojan is software that may appear legitimate but has come up with a trick to get itself downloaded. Then it activates and can delete files and steal data or offer the author access to your system.
- A rootkit can be unknowingly downloaded along with other programs you install. It can hide on your computer and avoid the normal means of detection. The attacker can then modify your schedules and access your data without your knowledge.
- A bot (or botnet) is a computer program that is automated. The attacker takes control of the computer or network and can distribute a virus or spam. Your personal information can be altered and can attack other computers on your network, sending spam emails to your list of email addresses.
- A worm usually does not damage the file on your computer, but it can take up huge amounts of hard disk space, slowing it down. It can travel very quickly through your network and access your email address book, spreading to all your contacts.
- The term spyware includes Trojans and tracking cookies. It does not usually transmit to other computers or networks, but it can disable antivirus software and cause other problems.
- Adware originates from advertising software and can produce pop-up windows or other annoyances.
Part 2 of 4: Use Good Security Habits on Your Computer to Prevent Malware
Step 1. Reduce the risk of getting malware on your computer by using a good antivirus program in the first place
Keep the software up to date, as new viruses are constantly being written. Ask your antivirus provider if they offer anti-rootkit software.
Step 2. Use excellent passwords
You have to make it difficult for an attacker to guess passwords. Use different passwords for different programs and always include a combination of lowercase and uppercase letters, numbers and symbols.
Never choose an option for which the computer can "remember" the password
Step 3. Use a firewall on your computer
If your computer offers this option, make sure it is enabled. The firewall can prevent an attack before it gets to your computer.
Part 3 of 4: Install New Antivirus Programs
Step 1. Download a different antivirus program than the one installed
Your regular antivirus may have missed the virus, so it's good practice to install a new and specific program.
- Malwarebytes is a great anti-malware program, free and easy to use. Download it from
- HitmanPro can remove rootkits. Download it from
- Kaspersky has a specific rootkit killer and can be downloaded automatically by going to
Step 2. Download these programs to another computer and copy the programs to a flash drive if you cannot connect to the Internet
You will need to put it on the infected computer for scanning.
Part 4 of 4: Remove the Malware
Step 1. Back up all files and data on your computer before starting the removal procedure
You can restore them if you can't find the problem and need to reinstall the operating system. Do not make copies of programs, system files or screen savers, as they may be infected. Back up device drivers. A utility called Double Driver will do this for you. Also, export emails and their settings to save them.
Step 2. Disconnect your computer from the Internet
Step 3. First scan your computer in normal mode
However, some types of malware will not allow you to do this.
Step 4. Scan your computer in Safe Mode with Networking
- Restart your computer and hold down the F8 key (if you're using Windows). Remember that you have to press this key before you see the Windows startup logo.
- Look for the Advanced Options screen and select the startup settings. Using the arrow keys, select "Safe Mode with Networking" and press "Enter".
Step 5. Delete your temporary files using the "Disk Cleanup" utility
You can find it by going to Start, All Programs, Accessories, System Utilities, Disk Cleanup. This can speed up the scanning process.
Step 6. Launch the new virus scanner you installed
Follow the process until it is completed. If the program has discovered viruses or malware, follow the instructions to eliminate them.
Step 7. Launch your usual virus scanner for a full scan
This can take 60 minutes or more to complete.
Advice
- If you are still having trouble after following all these steps or your computer is infected with a rootkit, you may need to reinstall Windows to remove a deeply hidden virus or malware.
- Check your Home Page before launching the web browser. Click on Start, Control Panel and Internet Options. If you don't recognize the home page, it may still be infected.
- After the malware is removed, you may also need to troubleshoot registry issues. A registry cleaner (CCleaner is a popular free option) can help with this task.