Anti-virus software can be an effective first response to protecting a device from a significant percentage of malware (a general term for all malicious software, including viruses, spyware, trojans, and other such threats). However, anti-virus software is generally considered ineffective against targeted attacks. Nevertheless, it remains a valuable defensive tool against non-targeted, but still dangerous, malware.  Below is a non-exhaustive list of options:

• Microsoft Safety Scanner (Windows)
• F-Secure
• Kaspersky
• ClamXav (Mac OS X)
• TrendMicro
• ClamAV (Windows and Linux)

When you run anti-virus software, ensure that it is up to date. If a virus is detected the following steps are recommended.

• Step 1: Ensure that your anti-virus software is up to date
• Step 2: Take a screenshot of the message
• Step 3: Continue with the recommended steps to remove the virus

(Adapted from the Digital First Aid Kit )