TROJ_MUTOPY.SMYN

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

Arrival Details

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

• %AppDataLocal%\{filename}
• %Application Data%\{filename}
• %Application Data%\Microsoft\{filename}
• %ProgramData%\{filename}
• %System Root%\Users\All Users\{filename}
• %System Root%\Users\All Users\Microsoft\{filename}
• %System%\drivers\{filename}
• %User Profile%\AppData\Local\Microsoft\{filename}
• %User Profile%\Local Settings\Application Data\{filename}
• %User Profile%\Local Settings\Application Data\Microsoft\{filename}
• %User Temp%\{filename}
• %Windows%\{filename}
• %Windows%\System\{filename}

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista and 7.. %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.. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %System% is the Windows system folder, which is usually C:\Windows\System32.. %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.. %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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Windows% is the Windows folder, which is usually C:\Windows.)

It drops the following non-malicious file:

• %User Temp%\Twain002.Mtx

(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

It creates the following folders:

• %User Temp%\~NwcTemp
• %User Temp%\~NwcTemp\conh09

(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
{value} = "{dropped copy}"

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
{value} = "{dropped copy}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
{value} = "{dropped copy}"

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
{value} = "{dropped copy}"

HKEY_CURRENT_USER\.DEFAULT\Software\
Microsoft\Windows\CurrentVersion\
Policies\Explorer\Run
{value} = "{dropped copy}"

HKEY_CURRENT_USER\.DEFAULT\Software\
Microsoft\Windows\CurrentVersion\
Policies\Explorer\Run
{value} = "{dropped copy}"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
{value} = "{dropped copy}" {value} = {blank}

(Note: The default value data of the said registry entry is {blank}.)

Download Routine

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

• http://{BLOCKED}al.store-apps.org/d/conh09.jpg

It saves the files it downloads using the following names:

• %User Temp%\~NwcTemp\conh09\conhost.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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

NOTES:

The {filename} mentioned above may be the folllowing:

• cisvc.exe
• clipsrv.exe
• cmstp.exe
• comrepl.exe
• csrss.exe
• dllhost.exe
• dllhst3g.exe
• esentutl.exe
• ieudinit.exe
• logman.exe
• mqtgsvc.exe
• mstinit.exe
• mstsc.exe
• rsvp.exe
• sessmgr.exe
• spoolsv.exe
• wininit.exe
• winlogon.exe

The {value} mentioned above may be the following:

• Cisvc
• ClipSrv
• CmSTP
• ComRepl
• DllHost3g
• DllHst
• Esent Utl
• IEudinit
• Logman
• Microsoft RSVP
• MqtgSVC
• MstInit
• Mstsc
• SessMgr
• Spool
• Spooler
• WinInit
• cisvc
• cisvc
• rsvp
• run