RE: Disabling autorun for mapped network drives

["tima" <tima.soni () gmail com>]

Hi Johnny,

We tested the group policy setting in our envirotment and it worked fine.
You should implement this in the local group policy of the images. 

Running a scan on the network and deleting all autorun.inf files might not
be the solution. Because you might have software dumps in the network shares
and that have legitimate autorun.inf files. 


Another solution is go to the following key in the registry
HKEY_CURRENT_USER-> Software -> Microsoft -> Windows ->CurrentVersion ->
Policies -> Explorer
Create a REG_DWORD - NoDriveTypeAutoRun , give it the following value -
0x10    
Then restart explorer. 

Regards,
Tima

-----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com] On
Behalf Of Johnny Wong
Sent: Thursday, July 26, 2007 7:33 AM
To: security-basics () securityfocus com
Subject: Disabling autorun for mapped network drives

Hello all,

Over the past few months, we have faced situations where user PCs 
were infected with virus when they connect to network mapped drives. 
What happened was that the virus creates "autorun.inf" in the root of 
the shared network drive, so users who double-click the drive in 
Explorer, the autorun.inf executes the linked virus-infected 
executable. Evem though the user PCs have anti-virus installed, the 
incidents we faced so far, the virus was not detectable. It was 
realised later that the virus was a new strain.

We have tried to disable the mapped-drives autorun feature (based on 
registry key settings); however, it was not foolproof because the 
autorun.inf was still able to execute in some cases. We found later 
from Microsoft's KB (http://support.microsoft.com/kb/933008) that 
this registry setting may not work. So we did not roll out this 
registry settings to the users.

Anyone of you facing the same situation as me? I can only think of 
the following solutions:

- keep AV signatures updated - this is not foolproof because most of 
the time, the virus writers are leading the game. So we can only try 
to send the first specimen we find ASAP to the AV vendors so that 
they could develop signatures for them. Guessed by that time, a 
number of users would have been infected.

- run a task on the file server that regularly checks for presence of 
autorun.inf in the root of the shared folders, and if found, rename 
or delete them. Implementation of this task will impact the 
performance of the server when it hosts a lot of shared folders.

Please share your workarounds if you have any.

Thank you,

JW