We ran a little test here at OPSWAT Labs earlier this week to help demonstrate why multi-scanning is so important.
First, we did a quick search on Google for keyloggers and downloaded four of them for our project. Next, we submitted allfour to our free, online file scanning solution, Metascan Online, and got dramatically different results.
Keylogger 1:  | Keylogger 2:  |
Keylogger 3:  | Keylogger 4:  |
None of the keyloggers was detected as a threat by all 31 engines, but most importantly, no single engine detected all four! The primary take-away from our test is simple…no single antivirus engine had perfect detection, but by multi-scanning with several engines, every threat was found.
Try it out for yourself at www.metascan-online.com!
You can view the results pages for our tests using the links below, but keep in mind that the results may change if the files are rescanned with more recent virus definitions from the engines:
