Virus and Security Solution Center

Microsoft Active Response for Security (MARS) initiative

This webpage, part of Project Mars, is dedicated to providing customers with information on how to remove malware from their computers, so the computers are no longer operating under the remote control of bot-herders.

Clean Your PC

If you believe your PC is infected with malware or want to make sure it isn’t, we recommend that you:

Scan your PC for viruses
The Microsoft Safety Scanner is a free downloadable security tool that provides on-demand scanning and helps remove viruses, spyware and other malicious software. If you are not able to download or run the Safety Scanner, additional information is provided in KB2916641.

Configure your PC to help prevent security threats
Building up your computer’s defenses helps secure your computer against viruses. To help prevent security threats from infecting your PC, the Malware Prevention Diagnostic Tool will guide you through configuring these system settings. Learn more about configuring your system settings here.
Protect your PC with Microsoft Security Essentials
Help protect your home and small business PCs from malicious software such as spyware, viruses, Trojans and rootkits with Microsoft Security Essentials. For additional antivirus software options, please visit the Consumer security software providers page.

Get Help

If you need additional support, contact the Microsoft Consumer Security Support Center.

Frequently Asked Questions

What is Project MARS?

The Microsoft Active Response for Security (MARS) initiative is focused on combining legal and technical acumen to proactively disrupt criminal infrastructure. This includes taking down botnets (armies of malware-infected PCs operating secretly under the remote control of a criminal), seizing the infrastructure and domains criminals use to control them and taking the information we gain in those efforts to help better protect the Internet community and our customers. Project MARS is a joint effort between the Microsoft Digital Crimes Unit, Microsoft Malware Protection Center, Customer Support Services and Trustworthy Computing. Recent examples of MARS include: Operation b49 (the Waledac takedown), Operation b107 (the Rustock takedown), Operation b79 (the Kelihos takedown) and Operation b71 (the Zeus disruption).

Why is this important to me?

If your computer is infected with malicious software, your personal information may be at risk. Your computer may also be a part of a botnet, which is a network of compromised computers controlled by a remote attacker. Botnets are one of the most serious online threats due to their ability to engage in distributed denial of service attacks, as well as steal sensitive information, distribute malicious software, log keystrokes, and send spam. We urge you to follow the recommended actions on this site to minimize the risk to your computer and personal information.

How does Microsoft know which computers are infected with botnets?

Through Microsoft's recent legal action, Microsoft has notice of IP addresses of computers potentially compromised by the Waledac and Rustock botnets. We have worked with major Internet Service Providers (ISP) and Computer Emergency Response Teams (CERT) across the world to notify computer users who may be infected by Waledac and Rustock. That process may have led you to this page.

Additional information on Project MARS and related operations

Virus information

Virus Information

Protect your computer with Microsoft Security Essentials software
With Microsoft Security Essentials, you get high-quality protection against viruses and spyware, including Trojans, worms and other malicious software. And best of all, there are no costs or annoying subscriptions to keep track of.

4 Steps to Protect Your Computer
Follow these four steps to keep your computer protected and up-to-date.

Think you have a virus? Follow these steps
This article discusses how to determine whether your computer is infected with a computer virus, worm or a Trojan, how to recover from an infection and how to prevent future infections from a computer virus.

Microsoft Consumer Online Safety
Protect your family, yourself and your computer by learning more about computer safety. The Consumer Online Safety web site provides useful tools and resources to get you up-to-date with PC safety and security.

Security information

Security Information

Diagnose and fix Windows security problems automatically
Automatically diagnose and fix problems with security in Windows, such as UAC (User Account Control), Windows Firewall or Data Execution Protection (DEP) to prevent security threats.

Security Checklist for Windows 7
Use this checklist to make sure you’re taking advantage of all the ways that Windows can help keep your computer as secure and safe as possible.

Install the latest Microsoft Security Patches
On the second Tuesday of each month Microsoft releases its latest security updates for its software. Ensure your computer is protected by installing the latest Security Bulletin from Microsoft.

Install Microsoft Updates
Protect your PC from security risks and ensure your version of Windows is up-to-date.

4 Steps to Protect Your Computer
Follow these four steps to keep your computer protected and up-to-date.

Microsoft Consumer Online Safety
Protect your family, yourself and your computer by learning more about computer safety. The Consumer Online Safety web site provides useful tools and resources to get you up-to-date with PC safety and security.

Protect your computer with Microsoft Security Essentials software
With Microsoft Security Essentials, you get high-quality protection against viruses and spyware, including Trojans, worms and other malicious software. And best of all, there are no costs or annoying subscriptions to keep track of.

Other security software providers

Microsoft wants to help ensure your PC is protected. If Windows Live OneCare and Microsoft Security Essentials do not meet your needs, learn more about other security software providers.

Antimalware apps for Windows 8 Release Preview

Windows 7 consumer security software providers

Windows Vista consumer security software providers

Windows XP consumer security software providers

Hoaxes and scams

Hoaxes and scams

Scams that use Microsoft’s name or product names
Phishing scams often include the names of well-known companies to convince you to visit spoofed Web sites or click on dangerous links. Microsoft does not send unsolicited e-mail requesting personal or financial information.

How to handle suspicious e-mail
Follow these guidelines to help protect yourself when suspicious mail shows up in your Inbox.

Scams that promise money, gifts, or prizes
Several types of phishing scams promise fantastic financial or other rewards in exchange for just a few small things you have to do…which include turning over your personal information to an identity thief.

How to recognize phishing e-mails or links
A few clues can help you spot fraudulent e-mail messages or links within them.

Frequently Asked Questions about Phishing
Find answers to the most popular questions about phishing.

How to Report Phishing
The Anti-Phishing Working Group is a volunteer organization that maintains a repository of phishing scam e-mails and websites. Report suspected phishing here.

Protect yourself from phishing scams and identity theft
Follow the steps on this page to protect your personal data such as credit card numbers, Windows Live IDs and passwords.

Ask the Community

Ask the Community

Security & Privacy forum at Microsoft Community
Post questions in the Microsoft Security and Privacy Community forum. Experts are on hand to help.


Getting Started with Microsoft Security Essentials forum at Microsoft Community
Post questions in the Getting Started and Upgrading with Microsoft Security Essentials Community forum. Experts are on hand to help.


Updating Virus and Spyware Definitions forum at Microsoft Community
Post questions in the Updating Virus and Spyware Definitions for Microsoft Security Essentials Community forum. Experts are on hand to help.


Scanning, Detecting and Removing Threats forum at Microsoft Community
Post questions in the Scanning, Detecting and Removing Threats with Microsoft Security Essentials Community forum. Experts are on hand to help.

IT Professionals

IT-Professional Security Resources

New Solution Accelerator: Microsoft Security Compliance Manager
Use the Microsoft Security Compliance Manager to provide centralized security baseline management features, a baseline portfolio, customization capabilities, and security baseline export flexibility to accelerate your organization’s ability to efficiently manage the security and compliance process for the most widely used Microsoft products.

Install the latest Microsoft Security Patches
On the second Tuesday of each month Microsoft releases its latest security updates for its software. Ensure your computer is protected by installing the latest Security Bulletin from Microsoft.

What’s New for Security in Windows Server 2008 R2
These product evaluation topics provide IT-Professionals with an overview of new and changed security related features in Windows Server 2008 R2.

Install Microsoft Updates
Protect your PC from security risks and ensure your version of Windows is up-to-date.

Microsoft Malware Protection Center
The Microsoft Malware Protection Center blog provides a real-time method for the Microsoft Malware Response Center to communicate with customers. Topics include day-to-day, “behind the scenes” information about new, emerging and interesting malware threats as well as other research topics in the computer security field.

Protect your Exchange messaging environment with Forefront Security for Exchange Server
Forefront Security for Exchange Server includes multiple scan engines from industry-leading security firms integrated in a single solution to help businesses protect their Exchange messaging environments from viruses, worms, and spam.

Security Checklist for Windows 7
Use this checklist to make sure you’re taking advantage of all the ways that Windows can help keep your computer as secure and safe as possible.

Stay secure: Visit the Security TechCenter on TechNet
The Security TechCenter provides links to technical bulletins, advisories, tools, prescriptive guidance, and community resources designed to help IT professionals keep Microsoft servers, desktops, and applications up to date and secure.

Assisted Support

Assisted Support


Answer Desk is an assisted support service available for you online or on the phone. All support services are provided by highly trained and friendly Answer Techs. We think we can resolve your virus problem with our Premium Software Support service. After diagnosing your issue, if appropriate, you will be offered the choice to purchase this service.
Get live assisted support for viruses

Contact Consumer Security Support
When creating a case, ensure that you provide all requested information related to the problem you are facing. In order to track and reference your inquiry, you will receive a support case number. This support case number will be required for all contacts with a Support Professional.
Hours: 24 hours a day, 7 days a week
Support Options

Assistance on other Microsoft Security Products
Microsoft Security Essentials

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Last Review : June 28, 2012