TROJ_DROPPER.SDQ

October 08, 2012
 Analysis by: Sabrina Lei Sioting
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan deletes itself after execution.

  TECHNICAL DETAILS

File Size:

45,568 bytes

File Type:

PE

Memory Resident:

No

Initial Samples Received Date:

13 Mar 2011

Installation

This Trojan drops the following files:

  • %System%\smslauc.dll - non-malicious files

(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.)

Autostart Technique

This Trojan registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\smservice

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\smservice
Type = "10"

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

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\smservice
ImagePath = "%System Root%\system32\svchost.exe -k smslaunch"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\smservice
DisplayName = "SecurityIdentification"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\smservice
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\smservice\Parameters

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\smservice\Parameters
ServiceDll = "%System Root%\System32\smslauc.dll"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\smservice\Security

Other Details

This Trojan deletes itself after execution.

  SOLUTION

Minimum Scan Engine:

8.900

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Restart in Safe Mode, and then delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • smservice

Step 3

Search and delete this file

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.
  • %System%\smslauc.dll

Step 4

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DROPPER.SDQ. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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