What threat does Generic!atr pose?

About 6 months ago I got a trojan/worm on my flash drive. I started having problems opening it - I couldn't click on it to open; I had to go through auto play each time. When I plugged my flash drive into my own laptop, Norton Antivirus alerted me that there was a virus on it. I went through the steps to clean it, and even double-checked and went through the system restore files. I never had NAV detect it again, but I kept having trouble opening my flash drive. Eventually my hard drive got old and broke, so I just got a new computer that has McAfee trial software on it instead of NAV. When I plugged in my flash drive McAfee told me that I had Generic!atr and removed it. Now I am able to open my flash drive normally again. So I'm wondering why didn't my NAV clean it like it said it did, why the trojan wasn't detected again, and what harm could it have done these past 6 months? I always kept my NAV updates current. I couldn't even find info on Generic!atr on Symantec's site. Thanks.

What threat does Generic!atr pose?norten

The trhreat is low for such worms.

All it done is to copy some lines in JavaScript in autorun.inf folder located on the flash drive.

This info then copy onto your hard drive and execute everytime you access your flash drive.

Windows by default has autorun option enable, so they read automatically any flash drive, CD/DVD disk etc.BY READING INFO containing in AUTORUN.INF file.