WORM_ONLING.DI

This worm arrives by connecting affected removable drives to a system. It may be dropped by other malware. It may be unknowingly downloaded by a user while visiting malicious websites.

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

Arrival Details

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

It may be dropped by other malware.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This worm drops the following files:

• %System%\mmvo.exe - copy of itself
• %System%\mmvo0.dll - detected as TSPY_LINEAGE.GEZ

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Autostart Technique

This worm creates the following registry entries to enable automatic execution of dropped component at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
mmva = %System%\mmvo.exe

Other System Modifications

This worm modifies the following registry entries to hide files with Hidden attributes:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 2

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = 0

(Note: The default value data of the said registry entry is 1.)

Propagation

This worm drops copies of itself in all removable and physical drives found in the system.

It drops the following copy of itself in all physical and removable drives:

• rrxf.cmd

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:

{garbage}
[AutoRun]
{garbage}
open=rrxf.cmd
{garbage}
shell\\open\\Command=rrxf.cmd
{garbage}
shell\\open\\Default=1
{garbage}
shell\\explore\\Command=rrxf.cmd
{garbage}