Malware Classification

Hello everyone

 

Recently I have been performing a few tests - just for interests sake - to see if how different companies classify 'malware' affects scanning and detection performance.

 

I particular piece of software that seems to be inconsistent is any keygen. I tried scanning one with Norton, came up with nothing, MawareByte's also came up with nothing, yet Ad-Aware Anniversary edition 2008, says it is a Trojan. I submitted this to Symantec, Tracking #10337615, and received a message telling me it was a keygen. Now, I also uploaded this to Virustotal, and it had a 30% hit rate. I then tried a different keygen, and it had a 20% hit rate. Now my question is, do companies classify malware at their own distinction? i.e. could a certain security company decide to attack all keygens, when other's don't, because they are, infact, not malware? what other files could be prone to this discrepancy?

 

A reply from a Symantec representative would be nice, as I am really curious (and a bit confused) as to how this works?