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TROJ_SIREFEF.YRM

September 09, 2013
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

56,454 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

09 Sep 2013

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.

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Google Update = "{random characters}"

It 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\?etadpug

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\WinRAR

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\?etadpug\Parameters

It adds the following registry entries:

HKEY_CURRENT_USER\Software\WinRAR
HWID = "{random values}"

HKEY_CURRENT_USER\Software\WinRAR
Client Hash = "{random values}"

HKEY_CURRENT_USER\Software\WinRAR
2221B8FD70793BF59958637739798BA8 = "{random values}"

HKEY_CURRENT_USER\Software\WinRAR
74EDD4739F6F1C226041180A6B89C928 = "{random values}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\?etadpug\Parameters
Parameters = "5ec"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\?etadpug
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\?etadpug
Type = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\?etadpug
ErrorControl = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\?etadpug
ImagePath = "{random characters}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\?etadpug
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\?etadpug
Description = "{random characters}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\?etadpug
DisplayName = "Google Update Service (gupdate)"

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\71953.exe
  • %User Temp%\79140.exe
  • GoogleUpdate.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.)

Other Details

This Trojan deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

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
    • ?etadpug
  • In HKEY_CURRENT_USER\Software
    • WinRAR
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\?etadpug
    • Parameters

Step 4

Delete this registry value

[ 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Google Update = "{random characters}"
  • In HKEY_CURRENT_USER\Software\WinRAR
    • HWID = "{random values}"
  • In HKEY_CURRENT_USER\Software\WinRAR
    • Client Hash = "{random values}"
  • In HKEY_CURRENT_USER\Software\WinRAR
    • 2221B8FD70793BF59958637739798BA8 = "{random values}"
  • In HKEY_CURRENT_USER\Software\WinRAR
    • 74EDD4739F6F1C226041180A6B89C928 = "{random values}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\?etadpug\Parameters
    • Parameters = "5ec"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\?etadpug
    • Start = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\?etadpug
    • Type = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\?etadpug
    • ErrorControl = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\?etadpug
    • ImagePath = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\?etadpug
    • ObjectName = "LocalSystem"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\?etadpug
    • Description = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\?etadpug
    • DisplayName = "Google Update Service (gupdate)"

Step 5

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %User Temp%\71953.exe
  • %User Temp%\79140.exe
  • GoogleUpdate.exe
  • @

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_SIREFEF.YRM. 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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