JS_AGENT.SMLS

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

It disables Task Manager, Registry Editor, and Folder Options. It creates certain registry entries to disable applications related to security. It modifies certain registry entries to hide file extensions.

It connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats. As of this writing, the said sites are inaccessible.

Arrival Details

This worm arrives via removable drives.

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:

• %User Startup%\{random filename}.js
• %Application Data%\{random folder name}\{random filename}.js
• %Program Files%\{random folder name}\{random filename}.js
• %All Users Profile%\Start Menu\Programs\Startup\{random filename}.js

(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.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).. %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)

It creates the following folders:

• %Application Data%\{random folder name}
• %Program Files%\{random folder name}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

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 filename} = %Application Data%\{random folder name}\{random filename}.js

Other System Modifications

This worm adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies
NoDispCPL = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion
SystemRestoreDisableSR = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Internet Explorer\Control Panel
HomePage = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows NT\SystemRestore
DisableConfig = "1"

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Internet Explorer\Control Panel
HomePage = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoWindowsUpdate = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoControlPanel = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies
DisableCMD = "1"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UpdatesDisableNotify = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusOverride = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallOverride = "1"

(Note: The default value data of the said registry entry is 0.)

It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NofolderOptions = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies
DisableTaskMgr = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies
DisableRegistryTools = "1"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"

(Note: The default value data of the said registry entry is 0.)

It creates the following registry entries to disable applications related to security:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
AntiVirusDisableNotify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
FirewallDisableNotify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
FirewallOverride = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\MRT
DontReportInfectionInformation = "1"

It modifies the following registry entries to hide file extensions:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = "1"

(Note: The default value data of the said registry entry is 0.)

Propagation

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

• {drive letter}:\{random folder name}\{random filename}.js

The said .INF file contains the following strings:

{garbage characters}
[autorun]
{garbage characters}
shell\open\command={random folder name}\{random filename}.js
{garbage characters}
shellexecute={random folder name}\{random filename}.js
{garbage characters}
open={random folder name}\{random filename}.js
{garbage characters}
shell\explore\command={random folder name}\{random filename}.js
{garbage characters}

Download Routine

This worm connects to the following malicious URLs:

• http://{BLOCKED}ps.com/a/
• http://{BLOCKED}.{BLOCKED}.13.158

As of this writing, the said sites are inaccessible.

Other Details

This worm connects to the following URL(s) to check for an Internet connection:

• http://google.com

It drops the following file(s)/component(s):

• %System Root%\{random folder name}\{random filename} - nonmalicious

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

NOTES:

It does not perform its intended routine if it is running in a Virtual Machine.

It creates LNK files in removable drives using names of exisiting folders in removable drives. The LNK file opens the dropped malware copy as well as the original folder.

The attribute of the original folders are set to hidden.

The following added registry entry disables user's access to the Control Panel:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
NoControlPanel= "1"

It checks for installed Anti-virus applications:

• %Program Files%\Malwarebytes' Anti-Malware
• %Program Files%\Panda Security
• %Program Files%\Kaspersky Lab
• %Program Files%\Microsoft Security Client
• %Program Files%\Webroot
• %Program Files%\Alwil Software
• %Program Files%\G-Data
• %Program Files%\Bitdefender
• %Program Files%\AVG
• %Program Files%\Trend Micro
• %Program Files%\Sophos
• %Program Files%\AVAST Software
• %Program Files%\F-Secure
• %Program Files%\Microsoft Security Essentials
• %Program Files%\COMODO
• %Program Files%\Symantec
• %Program Files%\Avira
• %Program Files%\McAfee
• %Program Files%\ESET
• %Program Files%\Spyware Doctor