WORM_BLADAB.ASKR

October 08, 2014
 Analysis by: Rika Joi Gregorio
 ALIASES:

BackDoor-FCEE!8DB27D23156C(McAfee), Trojan.Win32.Dynamer(Ikarus), a variant of MSIL/Bladabindi.Q trojan(Eset)

 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:

Downloaded from the Internet, Dropped by other malware, Copies itself in all available logical drives

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 logs a user's keystrokes to steal information.

  TECHNICAL DETAILS

File Size:

253,184 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

05 Oct 2014

Payload:

Compromises system security, Connects to URLs/IPs, 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 the following copies of itself into the affected system and executes them:

  • %Application Data%\WINDOWS.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.)

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

  • 2b84a7ed33f26a9ef98ff459e1950594

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
2b84a7ed33f26a9ef98ff459e1950594 = "%Application Data%\WINDOWS.exe" .."

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
2b84a7ed33f26a9ef98ff459e1950594 = "%Application Data%\WINDOWS.exe" .."

It drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\2b84a7ed33f26a9ef98ff459e1950594.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.)

Other System Modifications

This worm adds the following registry keys:

HKEY_CURRENT_USER\Software\2b84a7ed33f26a9ef98ff459e1950594

It adds the following registry entries:

HKEY_CURRENT_USER\Environment
SEEM_MASK_NOZONECHECKS = "1"

HKEY_CURRENT_USER\Software\2b84a7ed33f26a9ef98ff459e1950594
US = "@"

It creates the following registry entry(ies) to bypass Windows Firewall:

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

Propagation

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

  • {Drive Letter}:\! My Picutre.SCR

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
  • Unistall itself
  • Update itself
  • Terminate itself

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

  • http://{BLOCKED}h.{BLOCKED}o.org:1177

Dropping Routine

This worm drops the following file(s), which it uses for its keylogging routine:

  • %Application Data%\WINDOWS.exe.tmp

(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.)

Information Theft

This worm logs a user's keystrokes to steal information.

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

11.194.06

FIRST VSAPI PATTERN DATE:

07 Oct 2014

VSAPI OPR PATTERN File:

11.195.00

VSAPI OPR PATTERN Date:

07 Oct 2014

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
    • 2b84a7ed33f26a9ef98ff459e1950594

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\Environment
    • SEEM_MASK_NOZONECHECKS = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • 2b84a7ed33f26a9ef98ff459e1950594 = "%Application Data%\WINDOWS.exe" .."
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
    • 2b84a7ed33f26a9ef98ff459e1950594 = "%Application Data%\WINDOWS.exe" .."
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %Application Data%\WINDOWS.exe = "%Application Data%\WINDOWS.exe:*:Enabled:WINDOWS.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.
  • %Application Data%\WINDOWS.exe.tmp

Step 7

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