WORM_VBNA.SMTB

This worm is not capable of exploiting any known vulnerability on the system.

This worm arrives via removable drives. It may be downloaded by other malware/grayware/spyware from remote sites. It may be dropped by other malware.

It modifies registry entries to hide files with System and Read-only attributes.

It drops copies of itself into network drives. It drops copies of itself in all removable drives. 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 via removable drives.

It may be downloaded by other malware/grayware/spyware from remote sites.

It may be dropped by other malware.

Installation

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

• %User Profile%\{random file name}.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

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
{random file name} = %User Profile%\{random file name}.exe /{random character}

Other System Modifications

This worm modifies the following registry entries to hide files with System and Read-only attributes:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = 0

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

Propagation

This worm drops copies of itself into network drives.

It drops copies of itself in all removable drives.

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 characters}
[AutoRun]
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
actiON=View Files
{garbage characters}
{garbage characters}
{garbage characters}
shellexecute={random file name}.exe
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
IcoN=%System Root%\system32\ShELL32.dlL,4
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
UsEAutOplAY=1
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}
{garbage characters}

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Other Details

This worm does the following:

• Drops .LNK files that reference a copy of itself in removable drives. These dropped files use the names of the folders and files located on the said drive for their filenames. It then hides the original folders and files to further fool the users. In addition, it also uses the following names:
  • Documents.lnk
  • Music.lnk
  • New Folder.lnk
  • Passwords.lnk
  • Pictures.lnk
  • Video.lnk
  Note that these .LNK files bear the icon of a normal Windows folder in order to trick users into clicking them. This action, in turn, executes more copies of this worm.
• Modifies dropped copies of itself
• Drops AUTORUN.INF files into network drives
• Attempts to connect to ns1.{BLOCKED}1253.com via port 8000 to possibly inform remote attackers of the infection and to receive commands from them, which may lead to information theft or download of other files that can be malicious. As of this writing, however, the said site is inaccessible.

NOTES:
This worm is not capable of exploiting any known vulnerability on the system.