Antivirus Software: How To Protect Yourself Against Viruses

This article provides information on protecting yourself from viruses, malware, and other malicious software. It lists recommended protection software, helpful tips, and what to do next if you think you've been infected.

The University's recommended antivirus software for unmanaged computers is now Sophos. Support for the previously recommended software, Symantec, was discontinued in May 2022.

Faculty and Staff:  Computers purchased by the University will automatically have Crowdstrike (a centrally-managed antivirus program) installed on them. These computers will not need the software listed below.

For personal computers, Penn offers the site-licensed Sophos Home, free of charge, to members of the Penn community using the links below.

If you have questions or concerns please reach out to Wharton Computing using the links in Questions, below.

Antivirus Software

Most Antivirus software now requires a subscription. If you prefer not to maintain a subscription, we recommend using Sophos (free to members of the Penn Community) or Windows Defender (for Windows machines).

Faculty and Staff who are using a computer managed by Wharton Computing already have antivirus installed automatically and can skip this section.

Active Defenders

  • WindowsSophos Home is offered by the University for free. Best for Staff and Faculty use.
  • Windows 10/11 Windows Defender is the default antivirus software on Windows 10 & above. Best for Student use.
  • MacOSSophos Home is also offered for MacOS by the University.


  • MalwareBytes scans your computer for any potential malicious or suspicious software & processes.

Helpful Tips

Be Aware of Sites & Attachments

As computers become more networked and standardized, it gets easier and easier to catch computer viruses. You can get viruses from downloads over the internet, from opening e-mail attachments, or from another infected system or device.

Many self-propagating viruses will mail themselves to you before the original sender has discovered that his/her machine is infected. Be suspicious of any attachments, but be extra vigilant about inappropriate subject lines and attachment titles (for example, if someone you barely know sends you an e-mail called ILOVEYOU).

Back Up Data Frequently

Some viruses are so damaging that they will render your files useless or unrecoverable. In that case, your only hope of recovery is with back-ups made prior to infection. 

Update, update, update!

Microsoft & software developers frequently release patches to fix known issues for their services. These fixes include known security issues that may leave your computer or program vulnerable to viruses and other attacks. To manually update, press the Windows key + S ( Windows icon. + s),  type check for updates, and then click the Check for Updates setting.

Sophos Home

The University of Pennsylvania offers free antivirus software to faculty and staff in the form of Sophos Home. Below are the links to download this software, along with some Frequently Asked Questions. 

Faculty and Staff who are using a computer managed by Wharton Computing already have antivirus installed automatically and can skip this section. However, Sophos is available for personal use as well, so can be installed on non-managed machines.

Download Links

Wharton Computing recommends using this software on MacOS devices. Windows 10 & 11 devices are already protected by the built-in antivirus software, Windows Defender.

Note: If you're still running Windows 8/8.1, Wharton Computing recommends updating to Windows 10 for optimal performance if supported by your device.

Windows 8.1, 10, or 11
Windows 8.1, 10, or 11
Symantec logo

Sophos Home for Windows

Staff and Faculty

Windows Defender logo

Windows Defender

Symantec logo

Sophos Home for Mac


Sophos Home FAQs

What if I already have antivirus software? 

If you are satisfied with your current antivirus software and are able to update the virus definition files on a regular basis then you can continue the use of your current antivirus software, but you might need an additional anti-spyware program. If you are not able to update the virus definition files or your antivirus subscription is expired, you will need to switch to Sophos Home.

Why should I switch to Sophos Home?

The university pays for a Sophos Home subscription that includes virus definition updates and spyware scans in addition to virus scans. It is also supported by Wharton Computing, so you can get assistance with the program should you encounter any problems.

Will I get technical support if I switch to Sophos Home

Yes, Wharton Computing offers support for Sophos Home and will be able to help you install and configure the antivirus software. 

If your computer has a virus... 

Students: If you think you have a virus, please stay calm and follow the directions in our Virus Removal article. We also encourage you to call, email, or drop by our Support Office (SHDH 114) in person so we can help with the situation. 

Faculty & Staff: Please contact your Wharton Computing Representative or the Information Security and Privacy Team at


Students: visit the Student Computing Website.

Faculty: contact your Academic Distributed Representative (login required).

Staff: email

For more information regarding security threats and antivirus software, you can also contact the Wharton Information Security and Privacy Team at