ALIASES:

Trojan:Win32/Meredrop (Microsoft); W32.Imsolk.B@mm (Symantec); Trojan-Dropper.Win32.Agent.evwt (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Generic.KDV.210534 (FSecure)

 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.

  TECHNICAL DETAILS

File Size: 2,393,080 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 15 Nov 2012

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 creates the following folders:

  • %User Profile%\Application Data\TEMP
  • D:\QQBin

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{987623AB-8888-22d2-9CBD-0000F87A469H}
StubPath = "D:\QQBin\QQBin.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\Licenses

HKEY_CLASSES_ROOT\CLSID\{17A9F042-338C-4683-576F-E1BF4E4FA0AC}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{17A9F042-338C-4683-576F-E1BF4E4FA0AC}\InprocServer32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{17A9F042-338C-4683-576F-E1BF4E4FA0AC}\TypeLib

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{987623AB-8888-22d2-9CBD-0000F87A469H}

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{R7C0DB872A3F777C0} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{K7C0DB872A3F777C0} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{17A9F042-338C-4683-576F-E1BF4E4FA0AC}\InprocServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{ID361F6EAD3346F26} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{0D361F6EAD3346F26} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\advapi32.dll[MofResourceName] = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\mssmbios.sys[MofResource] = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\ipnat.sys[IPNATMofResource] = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\Drivers\HTTP.sys[UlMofResource] = "{random characters}"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
RFC1156Agent\CurrentVersion\Parameters
TrapPollTimeMilliSecs = "3a98"

(Note: The default value data of the said registry entry is 3a98.)

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{17A9F042-338C-4683-576F-E1BF4E4FA0AC}\Version

Dropping Routine

This Trojan drops the following files:

  • D:\QQBin\QQBin.exe

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

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

[ 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\Software
    • Licenses
  • In HKEY_CLASSES_ROOT\CLSID
    • {17A9F042-338C-4683-576F-E1BF4E4FA0AC}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{17A9F042-338C-4683-576F-E1BF4E4FA0AC}
    • InprocServer32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{17A9F042-338C-4683-576F-E1BF4E4FA0AC}
    • TypeLib
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {987623AB-8888-22d2-9CBD-0000F87A469H}

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{987623AB-8888-22d2-9CBD-0000F87A469H}
    • StubPath = "D:\QQBin\QQBin.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
    • {R7C0DB872A3F777C0} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
    • {K7C0DB872A3F777C0} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{17A9F042-338C-4683-576F-E1BF4E4FA0AC}\InprocServer32
    • ThreadingModel = "Apartment"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
    • {ID361F6EAD3346F26} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
    • {0D361F6EAD3346F26} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\advapi32.dll[MofResourceName] = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\DRIVERS\mssmbios.sys[MofResource] = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\DRIVERS\ipnat.sys[IPNATMofResource] = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • %System%\Drivers\HTTP.sys[UlMofResource] = "{random characters}"

Step 5

Restore this modified 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_LOCAL_MACHINE\SOFTWARE\Microsoft\RFC1156Agent\CurrentVersion\Parameters
    • From: TrapPollTimeMilliSecs = "3a98"
      To: TrapPollTimeMilliSecs = ""3a98""

Step 6

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.
  • D:\QQBin\QQBin.exe

Step 7

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Profile%\Application Data\TEMP
  • D:\QQBin

Step 8

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

Step 9

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{17A9F042-338C-4683-576F-E1BF4E4FA0AC}
    • Version


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