ALIASES:

Backdoor:MSIL/Bladabindi.B (Microsoft); W32/Worm-FHS!92EE1FB5DF21 (McAfee); Trojan.MSIL.Bladabindi.b (v) (Sunbelt); ILAgent (AVG)

 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: 26,624 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 01 Jul 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.

Installation

This Trojan drops the following copies of itself into the affected system:

  • %User Profile%\Application Data\Trojan.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} 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\CurrentVersion\Run
8515eb34d8f9de5af815466e9715b3e5 = "%User Profile%\Application Data\Trojan.exe .."

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
8515eb34d8f9de5af815466e9715b3e5 = "%User Profile%\Application Data\Trojan.exe .."

Other System Modifications

This Trojan deletes the following files:

  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.792.57734
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.792.57734
  • %User Profile%\v2.0.50727.42\security.config.cch.792.57906

(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%User Profile%\Application Data\Trojan.exe = "{random characters}"

Dropping Routine

This Trojan drops the following files:

  • %User Startup%\8515eb34d8f9de5af815466e9715b3e5.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

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 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
    • 8515eb34d8f9de5af815466e9715b3e5 = "%User Profile%\Application Data\Trojan.exe .."
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • 8515eb34d8f9de5af815466e9715b3e5 = "%User Profile%\Application Data\Trojan.exe .."
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %User Profile%\Application Data\Trojan.exe = "{random characters}"

Step 4

Search and delete this file

[ 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.
  • %User Startup%\8515eb34d8f9de5af815466e9715b3e5.exe

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_CLICKER.WS. 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 6

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.792.57734
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.792.57734
  • %User Profile%\v2.0.50727.42\security.config.cch.792.57906


Did this description help? Tell us how we did.