Keep a Clean Machine

Keeping your Internet-connected devices free from malware and infections makes the Internet safer for you and more secure for everyone.

The Keep a Clean Machine campaign is an ongoing effort to help everyone understand the importance of protecting Internet-connected devices from malware and infections – especially malware that connects your devices with botnets.

What Are Botnets?Botnets are networks of personal computers infected by malware and remote controlled by criminals. Botnets are used to send junk email (spam), attack websites and distribute more malware, among other things.

The malware used by botnets can infect your computer, turning it into a "bot" or "zombie," meaning your computer can become part of the botnet and help criminals do their dirty work.

To learn more about botnets, visit Microsoft Security's Botnet page and read the "Botnets 101: Everything You Need To Know" blog from StopBadware and the National Cyber Security Alliance.


Keep a Clean Machine
  • Keep security software current: Having the latest security software, web browser and operating system are the best defenses against viruses, malware and other online threats.
  • Automate software updates: Many software programs will automatically connect and update to defend against known risks. Turn on automatic updates if that’s an available option.
  • Protect all devices that connect to the Internet: Along with computers, smartphones, gaming systems and other web-enabled devices also need protection from viruses and malware.
  • Plug & scan: “USBs” and other external devices can be infected by viruses and malware. Use your security software to scan them.
Connect With Care
  • When in doubt, throw it out: Links in email, tweets, posts and online advertising are often the way cybercriminals compromise your computer. If it looks suspicious, even if you know the source, it’s best to delete or, if appropriate, mark as junk email.
  • Get savvy about WiFi hotspots: Limit the type of business you conduct and adjust the security settings on your device to limit who can access your machine.
If You Think You're Infected
  • Act quickly: If you are notified, become aware or suspect your computer is infected, take immediate steps to remove malware.


Here are some free resouces to see if your computer is infected:

AVG Free Antivirus
ESET Online Scanner
Kaspersky Virus Scanner
McAfee Security Scan
Qualys Browser Check
Sophos Free Security Tools
Symantec Security Scan
Trend Micro HouseCall Virus Scan

Norton by Spmantec: Power Eraser
VIPRE Rescue

Once your computer is malware-free, here are some suggestions to get you back on track:

  • Change your passwords. A strong password is a sentence that is at least 12 characters long. Focus on positive sentences or phrases that you like to think about and are easy to remember (for example, “I love country music.”). On many sites, you can even use spaces! And remember, unique account, unique password.
  • Make sure your antivirus software, operating system and web browsers are up to date.

Visit to report identity theft and get a recovery plan, and visit the Identity Theft Resource Center for free victim resources.