Analysis by: Karl Dominguez
ALIASES:

Backdoor:Win32/Poisonivy.E (Microsoft); Backdoor.Trojan (Symantec); Generic BackDoor!dic (McAfee)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This spyware may be dropped by other malware.

It opens a hidden instance of Internet Explorer to send stolen information to a certain site. It logs a user's keystrokes to steal information.

  TECHNICAL DETAILS

File Size: 40,960 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 16 May 2011

Arrival Details

This spyware may be dropped by the following malware:

  • TROJ_PIDIEF.JS

Installation

This spyware adds the following mutexes to ensure that only one of its copies runs at any one time:

  • DKJU&#FSA
  • DK^*FJK#S

It injects itself into the following processes as part of its memory residency routine:

  • Explorer.exe

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{5222790F-A997-73A0-9455-908F372ED960}
StubPath = %System%:mconfucheck.exe

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
bricks

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
bricks\Recent File List

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
bricks\Settings

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{5222790F-A997-73A0-9455-908F372ED960}

Information Theft

This spyware opens a hidden instance of Internet Explorer to send stolen information to the following site:

  • {BLOCKED}uecheck.7766.org
  • {BLOCKED}il.com.mailsserver.com

It logs a user's keystrokes to steal information.

NOTES:

This spyware drops a copy of itself as an Alternate Date Stream:

  • %System%:mconfucheck.exe

It saves the stolen information in the following Alternate Data Stream:

  • %System%:mconfucheck

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 8.160.06
FIRST VSAPI PATTERN DATE: 16 May 2011

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

Remove malware files dropped/downloaded by TSPY_BRICKS.A

    TROJ_PIDIEF.JS

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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_CURRENT_USER\Software
    • Local AppWizard-Generated Applications
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {5222790F-A997-73A0-9455-908F372ED960}

Step 5

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

NOTES:

To delete the Alternate Data Stream:

  1. Download streams.exe from http://technet.microsoft.com/en-us/sysinternals/bb897440
  2. Open a command prompt. To do this, click Start>Run, type cmd.exe in the text box provided, then press Enter.
  3. Go to the directory where you saved streams.exe and type:
    streams -d %System%

(Note: %System% is the Windows system folder, which is usually C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)


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