TROJ_COMFOO.A

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.

It injects its dropped file/component to specific processes.

It opens a hidden Internet Explorer window.

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

It deletes itself after execution.

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

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

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

Installation

This Trojan drops the following files:

• %System%\odbm.dll - BKDR_COMFOO.A
• %System%\msobj.sys - RTKT_COMFOO.A

(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.)

It injects its dropped file/component to the following processes:

• Iexplore.exe

Autostart Technique

This Trojan registers its dropped component as a system service to ensure its automatic execution at every system startup. It does this by creating the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msobj
ImagePath = "%System%\msobj.sys"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msobj
Type = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msobj
Start = "3"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msobj
ErrorControl = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msobj
DisplayName = "msobj"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msobj\Security
Security = "{hex values}"

Other System Modifications

This Trojan modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Netman
Start = "2"

(Note: The default value data of the said registry entry is 3.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Netman\Parameters
ServiceDll = "%System%\odbm.dll"

(Note: The default value data of the said registry entry is %System%\netman.dll.)

Backdoor Routine

This Trojan opens a hidden Internet Explorer window.

Dropping Routine

This Trojan executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

Other Details

This Trojan deletes itself after execution.