Win32/Autorun is a family of worms that spreads by copying itself to the mapped drives of an infected computer. The mapped drives may include network or removable drives.

There are no common symptoms associated with this threat. Alert notifications from installed antivirus software may be the only symptoms.

Spreads via…

Mapped drives

When the worm run on your computer, it enumerates all drives of the computer until a mapped drive is found. The worm attempts to copy itself to the mapped drive. Worm:Win32/Autorun then writes an autorun configuration file named 'autorun.inf' pointing to the worm executable. When the removable or networked drive is accessed from a computer supporting the Autorun feature, the malware is launched automatically.

Disable Autorun functionality

This threat attempts to spread via removable drives on computers that support Autorun functionality. This is a particularly common method of spreading for many current malware families. For information on disabling Autorun functionality, please see the following article:

http://support.microsoft.com/kb/967715/

Take these steps to help prevent infection on your computer.

To detect and remove this threat and other malicious software that may be installed on your computer, run a full-system scan with an appropriate, up-to-date, security solution. The following Microsoft products detect and remove this threat:

• Microsoft Security Essentials or, for Windows 8, Windows Defender
• Microsoft Safety Scanner

Recovering from recurring infections on a network

The following additional steps may need to be taken to completely remove this threat from an infected network, and to stop infections from recurring from this and other similar types of network-spreading malware:

1. Ensure that an antivirus product is installed on ALL computers connected to the network that can access or host shares.
2. Ensure that all available network shares are scanned with an up-to-date antivirus product.
3. Restrict permissions as appropriate for network shares on your network. For more information on simple access control, please see: http://technet.microsoft.com/library/bb456977.aspx.
4. Remove any unnecessary network shares or mapped drives.

Note: Additionally it may be necessary to temporarily change the permission on network shares to read-only until the disinfection process is complete.