Is this a usb virus or an update?

What exactly is the update message that you get when you insert the flash drive?

Were your cousin’s songs deleted from a hard drive or from his iPod? Were you using iTunes at the time?

There is no relationship between them; your cousin just wants a scapegoat.

If you connect an iDevice to any computer other than the one used to sync it, and you leave iTunes on it’s default behavior, it WILL get wiped clean. If you try to manually sync it to a copy of iTunes other than the one it’s registered to, it may get wiped. If you try using the Windows version of iTunes, then all bets are off.

It sounds like the “shortcut” you’re seeing on the desktop is part of the flash drive. A lot of flash drives come with their own software for backups, etc. You can try installing Malwarebytes or SuperAntiSpyware and scan the flash drive if you’re concerned, but it doesn’t sound like a virus. Also, @jerv is right, when plugging in an iDevice on someone elses computer it most likely will launch iTunes automatically and begin “syncing” the device which means it’ll wipe it.

Install Malwarebytes and run off some scans.