Analysis by: Mar Philip Elaurza

ALIASES:

Backdoor:MSIL/Bladabindi (Microsoft), MSIL/Bladabindi.L (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This worm 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: 408,576 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 29 Jan 2015
Payload: Drops files

Arrival Details

This worm 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 worm drops a copy of itself in the following folders using different file names:

  • %User Temp%\svchost.exe
  • %User Startup%\{malware file name}.exe
  • {Drive Letter}:\! My Picutre.SCR

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

It drops the following files:

  • %User Temp%\svchost.exe.tmp

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It terminates the execution of the copy it initially executed and executes the copy it drops instead.

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{malware file name} = "%User Temp%\svchost.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{malware file name} = "%User Temp%\svchost.exe"

Other System Modifications

This worm adds the following registry keys:

HKEY_CURRENT_USER\Software
{malware file name} =

It adds the following registry entries:

HKEY_CURRENT_USER\Environment
SEE_MASK_NOZONECHECKS = "1"

HKEY_CURRENT_USER\Software\ed695f7a0a96a421871268638e7cecd4
US = "@"

Propagation

This worm drops the following copy of itself in all physical and removable drives:

  • {drive letter}\! My Picutre.SCR

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.646.04
FIRST VSAPI PATTERN DATE: 12 Jul 2016
VSAPI OPR PATTERN File: 12.647.00
VSAPI OPR PATTERN Date: 13 Jul 2016

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Terminate a process file/s detected as WORM_BLADABINDI.NTW

[ Learn More ]

*Note: If the detected file/s is/are not displayed in theWindows Task Manager, continue doing the next steps.

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
    • {malware file name}

Step 5

Delete these registry values

[ 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {malware file name} = "%User Temp%\svchost.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • {malware file name} = "%User Temp%\svchost.exe"
  • In HKEY_CURRENT_USER\Environment
    • SEE_MASK_NOZONECHECKS = "1"

Step 6

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 Temp%\svchost.exe.tmp

Step 7

Scan your computer with your Trend Micro product to delete files detected as WORM_BLADABINDI.NTW. 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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