WORM_VESENLO.SOW

This worm arrives by connecting affected removable drives to a system. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

As of this writing, the said sites are inaccessible.

It logs a user's keystrokes to steal information.

Arrival Details

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

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

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

• %User Profile%\Wins7\msmm.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.)

It drops the following files:

• %Start Menu%\Programs\Startups\desktop.ini - non-malicious file

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

It creates the following folders:

• %User Profile%\Wins7
• %User Profile%\Wins7\shin
• %Start Menu%\Programs\Startups
• %User Profile%\Wins7\shin0 - dropped upon certain conditions

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

Autostart Technique

This worm drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

• %User Startup%\Sound Player.lnk

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

Other System Modifications

This worm adds the following registry entries:

HKEY_LOCAL_MACHINE\CurrentControlSet\services\
SharedAccess\Parameters\FirewallPolicy\
FirewallRules - Windows Vista and 7 only
{Random GUID} = "v{version number}|Action=Allow|Active=TRUE|Dir=In|Protocol=6|Profile=Private|App=%System\ftp.exe|Name=Windows%|"

HKEY_LOCAL_MACHINE\CurrentControlSet\services\
SharedAccess\Parameters\FirewallPolicy\
FirewallRules - Windows Vista and 7 only
{Random GUID 2} = "v{version number}|Action=Allow|Active=TRUE|Dir=In|Protocol=17|Profile=Private|App=%System\ftp.exe|Name=Windows%|"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List - Windows OS other than Vista and 7
%System%\ftp.exe = "%System%\ftp.exe:*:Enabled:Windows"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\AppCompatFlags\
Layers
%System%\cmd.exe = "RUNASADMIN"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\AppCompatFlags\
Layers
%User Profile%\Wins7\msmm,exe = "ELEVATECREATEPROCESS"

Propagation

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

• {drive letter}:\New.exe

Dropping Routine

This worm drops the following files wherein it saves the information it gathers:

• %User Profile%\Wins7\shin\sss.col - encrypted keylogs
• %User Profile%\Wins7\shin0\sss.col - encrypted keylogs. dropped upon certain conditions

(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.)

Download Routine

This worm connects to the following URL(s) to download its component file(s):

• {BLOCKED}p.{BLOCKED}q.com

It saves the files it downloads using the following names:

• %User Profile%\Wins7\bil.col

(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.)

As of this writing, the said sites are inaccessible.

Information Theft

This worm logs a user's keystrokes to steal information.

Drop Points

This worm uploads files to the following File Transfer Protocol (FTP) sites:

• ftp.drivehq.com

NOTES:

It monitors the following browser and instant messaging client:

• Internet Explorer
• Yahoo Messenger

It steals from the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion
Values: ProductName
CSDVersion

HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System
Values: SystemBiosVersion

HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0
Value: ProcessorNameString

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography
Value: MachineGUID

The conditions mentioned above are the following:

• Date: May 10
• Year: 2008 onwards
• Time: 3:12 AM

Once the conditions are met, the malware will log the keystrokes to the newly dropped file and send the previously stolen information.

It attempts to check for the following analysis tools:

• File Monitor
• Process Monitor
• Registry Monitor