Analysis by: Abraham Latimer Camba

 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: 73,216 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 07 Mar 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 drops and executes the following files:

  • %Program Files%\Trusteer\Rapport\bin\RapportService.exe
  • %Windows%\RPService.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).. %Windows% is the Windows folder, which is usually C:\Windows.)

It drops the following copies of itself into the affected system:

  • %System%\{random hex value}.exe
  • %User Temp%\{random hex value}.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %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.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
load = "%User Temp%\{random hex value}.exe,"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random hex value} = "%System%\{random hex value}.exe,"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,%System%\{random hex value}.exe,"

(Note: The default value data of the said registry entry is "%System%\userinit.exe,".)

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_CLASSES_ROOT\.eze
@ = "MyEze.1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RapportMgmtService.exe
Debugger = "RPService.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RapportService.exe
Debugger = "RPService.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RapportSetup.exe
Debugger = "RPXService.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RapportSetup-Full.exe
Debugger = "RPXService.exe"

HKEY_CLASSES_ROOT\MyEze.1\shell\
open\command
@ = "%System%\RPService.exe %0 %1 %2"

It adds the following registry keys as part of its installation routine:

HKEY_CLASSES_ROOT\MyEze.1

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\RapportCerberus_29574

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\RapportEI

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\RapportKELL

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\RapportMgmtService

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\RapportPG

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RapportMgmtService.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RapportService.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RapportSetup.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
RapportSetup-Full.exe

HKEY_CLASSES_ROOT\.eze

Other Details

This Trojan deletes itself after execution.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.820.06
FIRST VSAPI PATTERN DATE: 07 Mar 2012
VSAPI OPR PATTERN File: 8.821.00
VSAPI OPR PATTERN Date: 07 Mar 2012

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

Scan your computer with your Trend Micro product and note files detected as TROJ_DROPPER.UOY

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • RapportCerberus_29574
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • RapportEI
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • RapportKELL
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • RapportMgmtService
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • RapportPG
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • RapportMgmtService.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • RapportService.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • RapportSetup.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • RapportSetup-Full.exe
  • In HKEY_CLASSES_ROOT
    • .eze
  • In HKEY_CLASSES_ROOT
    • MyEze.1

Step 5

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 NT\CurrentVersion\Windows
    • load = "%User Temp%\{random hex value}.exe,"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {random hex value} = "%System%\{random hex value}.exe,"

Step 6

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator’s help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: Userinit = "%System%\userinit.exe,%System%\{random hex value}.exe,"
      To: Userinit = "%System%\userinit.exe,"

Step 7

Search and delete files detected as TROJ_DROPPER.UOY

[ 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.

Step 8

Search and delete these files

[ Learn More ]
There may be some 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.
  • %Program Files%\Trusteer\Rapport\bin\RapportService.exe
  • %Windows%\RPService.exe

Step 9

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