W32/Autorun.worm is capable of spreading through removable devices and network shares.

Autorun worms when executed can drop files into the %system% folder. The worm can also drop a copy of itself along with an AutoRun.inf configuration file in all removable devices, the root of all fixed drives and the system folders.

"Autorun.inf" is a text based configuration file which instructs the Windows operating system to perform some action upon opening a network shared drive, local folder, floppy drive, CD-ROM drive or the insertion of a removable disk drive. This configuration file is usually intended as a convenience feature, however is often misused by malware authors to create malware that spread automatically without any user interaction.

More information can be found at this McAfee page.