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WORM_BLADABINDI.D

February 01, 2016
 Analysis by: Pearl Charlaine Espejo
 ALIASES:

Trojan:Win32/Comrerop!gmb (Microsoft); Trojan.Win32.Comitsproc (Ikarus); Trojan.Comrerop.r3 (CAT-QuickHeal); TR/MSIL.Zapchast.aalh (Avira)

 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet


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.

It executes commands from a remote malicious user, effectively compromising the affected system.

It gathers information and reports it to its servers.

  TECHNICAL DETAILS

File Size:

114,688 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

27 Jan 2016

Payload:

Steals information, Connects to URLs/IPs

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 the following file(s)/component(s):

  • {Malware Path}\.tmp - Contains logged key strokes

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

  • %Application Data%\svchost.exe
  • %User Startup%\23556fb1360f366337f97c924e76ead3.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • 23556fb1360f366337f97c924e76ead3

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
23556fb1360f366337f97c924e76ead3 = ""%Application Data%\svchost.exe" .."

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
23556fb1360f366337f97c924e76ead3 = ""%Application Data%\svchost.exe" .."

Other System Modifications

This worm adds the following registry keys:

HKEY_CURRENT_USER\Software\23556fb1360f366337f97c924e76ead3

It adds the following registry entries:

HKEY_CURRENT_USER\Environment
SEE_MASK_NOZONECHECKS = "1"

HKEY_CURRENT_USER\Software\23556fb1360f366337f97c924e76ead3
US = "{Default}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Application Data%\svchost.exe = "%Application Data%\svchost.exe:*:Enabled:svchost.exe"

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • {Removable Drive Letter}:\23556fb1360f366337f97c924e76ead3.exe

Backdoor Routine

This worm executes the following commands from a remote malicious user:

  • Download and execute files
  • Compress files for uploading
  • Load plugins
  • Ping
  • Registry management
  • Remote shell execution
  • Restart
  • Screenshot
  • Uninstall itself
  • Update itself
  • Terminate itself

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • {BLOCKED}.zapto.org:2222
  • {BLOCKED}.{BLOCKED}.99.26:2222

Other Details

This worm gathers the following information and reports it to its servers:

  • Computer Name
  • User Name
  • Country
  • Volume Serial Number
  • Operating System Version
  • Application Name and Date of logged keystrokes

NOTES:

It hides the dropped copy of the malware found in removable drive.

It creates .LNK (shortcut) files using existing files found in removable drives. It uses the original filenames and file extensions and appends .LNK after. It then hides the original files tricking users to click .LNK files. This .LNK files point out to a hidden dropped copy of itself in the removable drive.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.302.06

FIRST VSAPI PATTERN DATE:

28 Jan 2016

VSAPI OPR PATTERN File:

12.303.00

VSAPI OPR PATTERN Date:

29 Jan 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

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
    • 23556fb1360f366337f97c924e76ead3

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\CurrentVersion\Run
    • 23556fb1360f366337f97c924e76ead3 = ""%Application Data%\svchost.exe" .."
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • 23556fb1360f366337f97c924e76ead3 = ""%Application Data%\svchost.exe" .."
  • In HKEY_CURRENT_USER\Environment
    • SEE_MASK_NOZONECHECKS = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %Application Data%\svchost.exe = "%Application Data%\svchost.exe:*:Enabled:svchost.exe"

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.
  • {Malware Path}\.tmp
  • {Removable Drive Letter}:\{existing file name and extension}.lnk

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_BLADABINDI.D. 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 8

  1. Open a command prompt.
    • For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run. In the Search box, type CMD then press Enter.
    • For Windows Vista, Windows 7, and Windows Server 2008 users, click Start, type CMD in the Search input field then press Enter.
    • For Windows 8, Windows 8.1, and Windows Server 2012 users, right-click on the lower-left corner of the screen, click Command Prompt.
  2. In the CMD console, type the following:

    ATTRIB [+R | -R] [+A | -A ] [+S | -S] [+H | -H] [+I | -I] [drive:][path][file name] [/S [/D] [/L]]

    Where:
    + Sets an attribute.
    - Clears an attribute
    R Read-only file attribute
    A Archive file attribute
    S System file attribute
    H Hidden file attribute
    I Not content indexed file attribute
    [drive:][path][filename]
    Specifies a file or files for attrib to process
    /S Processes matching files in the current folder and all subfolders.
    /D Processes folders
    /L Work on the attributes of the Symbolic Link versus the target of the Symbolic Link
    Example:
    To unhide all files and folders (including subfolders) in drive D:
    ATTRIB –H D:\* /S /D
  3. Repeat Step 3 for folders and files in other drives or folders.

NOTES:

Restore the attributes of the hidden files found in the removable drive.


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