Below is a list of free Anti-Virus & and Anti-Malware programs that have received high recommendations. You can run two or more anti-virus scans on potentially infected computer(s).
Kaspersky : http://www.kaspersky.com/virusscanner
Avast! Antivirus : http://www.avast.com
AVG Anti-Virus : http://free.avg.com
Trend Micro : http://housecall.trendmicro.com
MalwareBytes and ComboFix are anti-malware programs (with free versions) that have had known success in detecting recent strains of malware.
ComboFix : http://www.bleepingcomputer.com/combofix/
MalwareBytes : http://www.malwarebytes.org
If you are using an Apple computer, the following program is available.
ClamXav : http://www.clamxav.com