WORM_AUTORUN.ZZS

This worm arrives by connecting affected removable drives to a system.

It drops copies of itself into all the removable drives connected to an affected system. It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

It deletes itself after execution.

Arrival Details

This worm arrives by connecting affected removable drives to a system.

Installation

This worm drops the following copies of itself into the affected system:

• {drive}:\wyskq6lt.exe
• %User Temp%\herss.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

It drops the following component file(s):

• %User Temp%\cvasds{random number}.dll - detected as TROJ_GAMETHI.GST

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

It injects threads into the following normal process(es):

• Explorer.exe

Autostart Technique

This worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
cdoosoft = %User Temp%\herss.exe

Propagation

This worm drops copies of itself into all the removable drives connected to an affected system.

It drops the following copy(ies) of itself in all removable drives:

• wyskq6lt.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[AutoRun]
open=wyskq6lt.exe
shell\open\Command=wyskq6lt.exe

Dropping Routine

This worm sets the attributes of its dropped file(s) to the following:

• Hidden
• Read-Only
• System

Other Details

This worm deletes itself after execution.