Talk about timing...
I read this post around Wednesday and saved the link as a reminder that I needed to update the anti-virus software on one of my laptops. Well on Friday I managed to get attacked by two different virus/malware programs. A tricky issue was that the virus prevented me from executing any programs, and also blocked access to the internet.
I had Malwarebytes installed on the machine, but the definitions were outdated, and I couldn't download them. I had no antivirus s/w on the machine (I know, dumb) because in the past I attempted to install the free Symantec package that the university offers, but I could never get it to install.
Luckily I had another working computer. Rebooted the infected one in safe mode. Managed to manually copy a current MWB definitions file to the infected machine- luckily found links on Google that told me how to do this. One malicious program was relatively easy to remove manually. The other one was not, but once I got MWB to run, it found it. MWB also found and remove 11 other items.
Then I installed and ran Avira. It found 11 more.
Then I installed and ran Avast. It found 7 more.
Moral of the story, run anti-virus and malwarebytes regularly!