Analysis by: Pearl Charlaine Espejo

ALIASES:

Win32/Spy.Bebloh.O (ESET-NOD32); BackDoor.Bebloh.272 (DrWeb)

 PLATFORM:

Windows

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

  TECHNICAL DETAILS

File Size: 181,076 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 24 Oct 2016

Arrival Details

This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

Installation

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

  • %Application Data%\{random string}.exe
    (Note: Creation of this copy is triggered when the affected system is shutting down)

(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.)

Autostart Technique

This spyware creates the following registry entries to enable automatic execution of dropped component at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random string} = "%Application Data%\{random string}.lnk”
(Note: Creation of this registry entry is triggered when the affected system is shutting down)

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\{random key}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\{random key}
{random value} = "{hex values}"

HKEY_CURRENT_USER\Software\{random key}
(Default) = "{hex values}"

Dropping Routine

This spyware drops the following files:

  • %Application Data%\{random string}.lnk <- points to the copy
    (Note: Creation of this file is triggered when the affected system is shutting down, appends parameter "-autorun" to executed copy)

(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.)

Download Routine

This spyware saves the files it downloads using the following names:

  • %User Temp%\mslegasy.exe
  • %User Temp%\printtue.exe

(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.)

Other Details

This spyware connects to the following URL(s) to check for an Internet connection:

  • www.google.com

It connects to the following possibly malicious URL:

  • http://www.{BLOCKED}ickekocary.cz/hudba/mslegasy.exe
  • http://www.{BLOCKED}dienst-ana.de/wpimages/printtue.exe
  • {Random Generated Domain}.com
  • {Random Generated Domain}.net
  • https://{BLOCKED}n1vwssx9.net/auth/

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.856.02
FIRST VSAPI PATTERN DATE: 24 Oct 2016
VSAPI OPR PATTERN File: 12.857.80
VSAPI OPR PATTERN Date: 25 Oct 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. 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_CURRENT_USER\Software
    • {random key}

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
    • {random string} = "%Application Data%\{random string}.lnk"

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%\mslegasy.exe
  • %User Temp%\printtue.exe
  • %Application Data%\{random string}.lnk

Step 7

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