Analysis by: Rika Joi Gregorio
 Modified by: RonJay Kristoffer Caragay
ALIASES:

AdWare.Win32.Bromngr.b (Kaspersky), Bprotector (fs) (Sunbelt), a variant of Win32/bProtector.B application (Eset), Adware.GoonSquad (Norton), Adware/Bromngr (Fortinet), App/BProtect-B (Webroot)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Adware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

This adware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It arrives as a component bundled with malware/grayware packages. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 2,716 bytes
File Type: Other
Initial Samples Received Date: 02 May 2013
Payload: Downloads files

Arrival Details

This adware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It arrives as a component bundled with malware/grayware packages.

It may be downloaded from the following remote sites:

  • http://www.{BLOCKED}ystem.com/builds/2063B90/pack.7z
  • http://{BLOCKED}szq85hyn.cloudfront.net/builds/2063B90/pack.7z

However, as of this writing, the said sites are inaccessible.

Installation

This adware drops the following file(s)/component(s):

  • %User Temp%\ns{random letter}{random numbers}.tmp\babylon.dll - deleted immediately after dropping, also detected as ADW_BPROTECT

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

It drops the following non-malicious files:

  • %User Temp%\ns{random letter}{random numbers}.tmp\installutils.dll - deleted after dropping
  • %User Temp%\ns{random letter}{random numbers}.tmp\InetLoad.dll - deleted after dropping

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

It creates the following folders:

  • %User Temp%\ns{random letter}{random numbers}.tmp

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

Autostart Technique

This adware registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\ {4D2D3B0F-69BE-477A-90F5-FDDB05357975}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
kerberos_bho.ProtectorBHO

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
kerberos_bho.ProtectorBHO\CLSID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
kerberos_bho.ProtectorBHO\CurVer

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
kerberos_bho.ProtectorBHO.1

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
AppID\kerberos_bho.DLL

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
AppID\{BD56B5F0-BF3B-4AE5-A26D-FF92250A465E}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}\InprocServer32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}\ProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}\Programmable

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}\TypeLib

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}\VersionIndependentProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{8A556DF6-9025-45A8-9977-51DBEA33AFEA}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{8A556DF6-9025-45A8-9977-51DBEA33AFEA}\ProxyStubClsid

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{8A556DF6-9025-45A8-9977-51DBEA33AFEA}\ProxyStubClsid32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{8A556DF6-9025-45A8-9977-51DBEA33AFEA}\TypeLib

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}\1.0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}\1.0\
0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}\1.0\
0\win32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}\1.0\
FLAGS

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}\1.0\
HELPDIR

It adds the following registry entries to install itself as a Browser Helper Object (BHO):

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
kerberos_bho.ProtectorBHO
Default = "ProtectorBHO Class"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
kerberos_bho.ProtectorBHO\CLSID
Default = "{4D2D3B0F-69BE-477A-90F5-FDDB05357975}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
kerberos_bho.ProtectorBHO\CurVer
Default = "kerberos_bho.ProtectorBHO.1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
kerberos_bho.ProtectorBHO.1
Default = "ProtectorBHO Class"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
kerberos_bho.ProtectorBHO.1\CLSID
Default = "{4D2D3B0F-69BE-477A-90F5-FDDB05357975}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
AppID\kerberos_bho.DLL
AppID = "{BD56B5F0-BF3B-4AE5-A26D-FF92250A465E}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}
Default = "kerberos_bho"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}
Default = "ProtectorBHO Class"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}\InprocServer32
Default = "{malware path}\kerberos_bho.dll"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}\InprocServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}\ProgID
Default = "kerberos_bho.ProtectorBHO.1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}\TypeLib
Default = "{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4D2D3B0F-69BE-477A-90F5-FDDB05357975}\VersionIndependentProgID
Default = "kerberos_bho.ProtectorBHO"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{8A556DF6-9025-45A8-9977-51DBEA33AFEA}
Default = "IProtectorBHO"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{8A556DF6-9025-45A8-9977-51DBEA33AFEA}\ProxyStubClsid
Default = "{00020424-0000-0000-C000-000000000046}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{8A556DF6-9025-45A8-9977-51DBEA33AFEA}\ProxyStubClsid32
Default = "{00020424-0000-0000-C000-000000000046}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{8A556DF6-9025-45A8-9977-51DBEA33AFEA}\TypeLib
Default = "{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{8A556DF6-9025-45A8-9977-51DBEA33AFEA}\TypeLib
Version = "1.0"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}\1.0
Default = "kerberos_bho 1.0 Type Library"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}\1.0\
0\win32
Default = "{malware path}\kerberos_bho.dll"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}\1.0\
FLAGS
Default = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}\1.0\
HELPDIR
Default = "{malware path}"

Download Routine

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

  • %User Temp%\ns{random letter}{random numbers}.tmp\pack.7z - updated copy of ADW_BPROTECT

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

It downloads a possibly malicious file from a certain URL. The URL where this malware downloads the said file depends on the following parameter(s) passed on to it by its components:

  • /update=1

NOTES:

kerberos_bho.dll is its Internet Explorer BHO (Browser Helper Object) component which when installed will create the registry entries mentioned above.

bProtector.xpi is its Firefox Add-on component which when installed adds the following folders and files:

[Folders]

  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\content

[Files]

  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\chrome.manifest
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-10.0.2.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-11.0.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-12.0.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-13.0.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-14.0.1.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-15.0.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-3.6.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-3.6.xpt
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-5.0.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-6.0.2.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-7.0.1.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-8.0.1.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\components\bprotector-9.0.1.dll
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\content\bprotector.js
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\content\overlay.xul
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}\install.rdf

spext.crx is its Chrome extension component which when installed adds the following folder and files:

[Folder]

  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\pgafcinpmmpklohkojmllohdhomoefph

[Files]

  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\pgafcinpmmpklohkojmllohdhomoefph\1.0_0
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\pgafcinpmmpklohkojmllohdhomoefph\1.0_0\background.html
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\pgafcinpmmpklohkojmllohdhomoefph\1.0_0\background.js
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\pgafcinpmmpklohkojmllohdhomoefph\1.0_0\manifest.json
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\pgafcinpmmpklohkojmllohdhomoefph\1.0_0\spext.dll

It disguises itself as a BHO, add-on or extension for the above mentioned browsers.

It monitors Internet activity and modify the browsers' search engine settings.

  SOLUTION

Minimum Scan Engine: 9.700
SSAPI PATTERN File: 1.398.15
SSAPI PATTERN Date: 02 May 2013

Step 1

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 2

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 3

Close all opened browser windows

Step 4

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects
    • {4D2D3B0F-69BE-477A-90F5-FDDB05357975}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes
    • kerberos_bho.ProtectorBHO
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\AppID
    • kerberos_bho.DLL
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\AppID
    • BD56B5F0-BF3B-4AE5-A26D-FF92250A465E}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
    • {4D2D3B0F-69BE-477A-90F5-FDDB05357975}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
    • {8A556DF6-9025-45A8-9977-51DBEA33AFEA}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
    • {BFCFC139-033E-4A6D-BAA2-C6AAD53A1EDD}

Step 5

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Application Data%\Mozilla\Firefox\Profiles\{random value}.default\extensions\{0F827075-B026-42F3-885D-98981EE7B1AE}
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\pgafcinpmmpklohkojmllohdhomoefph
  • %User Temp%\ns{random letter}{random numbers}.tmp

Step 6

Scan your computer with your Trend Micro product to delete files detected as ADW_BPROTECT. 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 7

Search and delete these files

[ 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%\ns{random letter}{random numbers}.tmp\babylon.dll

NOTES:

Please add the following as Step 2 in Solution:

For IE users:

1. Open Internet Explorer.

2. Go to Tools > Manage Add-ons....

3. Select ProtectorBHO Class and Tick Disable under Settings pane.

For Firefox users:

1. Open Firefox.

2. Go to Tools > Add-ons.

3. Select Protector and click Uninstall.

For Chrome users:

1. Click the Chrome menu on the browser toolbar.

2. Click Tools.

3. Select Extensions.

4. Click Uninstall below the BrowserProtect extension.

5. A confirmation dialog appears, click Uninstall.


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