TROJ_BHO.UW

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

File Size:

281,607 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

12 Sep 2012

Arrival Details

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

Autostart Technique

This Trojan 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\{79848780-3218-4973-9C99-627926B6F4A4}

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Bind

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects

HKEY_CLASSES_ROOT\whatwedo.1

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
whatwedo.1\CLSID

HKEY_CLASSES_ROOT\whatwedo

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
whatwedo\CLSID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
whatwedo\CurVer

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{79848780-3218-4973-9C99-627926B6F4A4}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{79848780-3218-4973-9C99-627926B6F4A4}\ProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{79848780-3218-4973-9C99-627926B6F4A4}\VersionIndependentProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{79848780-3218-4973-9C99-627926B6F4A4}\Programmable

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{79848780-3218-4973-9C99-627926B6F4A4}\InprocServer32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{79848780-3218-4973-9C99-627926B6F4A4}\TypeLib

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0\
FLAGS

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0\
0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0\
0\win32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0\
HELPDIR

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}\ProxyStubClsid

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}\ProxyStubClsid32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}\TypeLib

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{D94C46A3-F89B-45C2-962A-76E300DC5C40}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{D94C46A3-F89B-45C2-962A-76E300DC5C40}\ProxyStubClsid

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{D94C46A3-F89B-45C2-962A-76E300DC5C40}\ProxyStubClsid32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{D94C46A3-F89B-45C2-962A-76E300DC5C40}\TypeLib

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{79848780-3218-4973-9C99-627926B6F4A4}\InprocServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}\TypeLib
Version = "1.0"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{D94C46A3-F89B-45C2-962A-76E300DC5C40}\TypeLib
Version = "1.0"

Dropping Routine

This Trojan drops the following files:

%System%\eyfwin.dll
%Windows%\ios.dat
%System%\p.ico
%Desktop%\SMS TRAP.url
%Favorites%\SMS TRAP.url
%Start Menu%\SMS TRAP.url
%System%\sf.ico
%Desktop%\Cheap Software.url
%Favorites%\Cheap Software.url
%Start Menu%\Cheap Software.url
%System%\c.ico
%Desktop%\VIP Casino.url
%Favorites%\VIP Casino.url
%Start Menu%\VIP Casino.url
%System%\m.ico
%Desktop%\Cheap Pharmacy Online.url
%Favorites%\Cheap Pharmacy Online.url
%Start Menu%\Cheap Pharmacy Online.url
%System%\m3.ico
%Desktop%\MP3 Download.url
%Favorites%\MP3 Download.url
%Start Menu%\MP3 Download.url
%System%\s.ico
%Desktop%\Search Online.url
%Favorites%\Search Online.url
%Start Menu%\Search Online.url
%User Temp%\ieF6C.tmp

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %Desktop% is the current user's desktop, which is usually C:\Windows\Profiles\{user name}\Desktop on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Desktop on Windows NT, and C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003.. %Favorites% is the current user's Favorites folder, which is usually C:\Windows\Favorites on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Favorites on Windows NT, and C:\Documents and Settings\{user name}\Favorites on Windows 2000, XP, and Server 2003.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Profiles\{user name}\Start Menu on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu on Windows NT and C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003.. %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.)

Other Details

This Trojan connects to the following possibly malicious URL:

http://{BLOCKED}updatestart.com/cfg1.php

This report is generated via an automated analysis system.

Minimum Scan Engine:

9.200

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Close all opened browser windows

Step 3

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\Microsoft
- Bind

In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer
- Browser Helper Objects

In HKEY_CLASSES_ROOT
- whatwedo.1

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\whatwedo.1
- CLSID

In HKEY_CLASSES_ROOT
- whatwedo

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\whatwedo
- CLSID

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\whatwedo
- CurVer

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
- {79848780-3218-4973-9C99-627926B6F4A4}

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{79848780-3218-4973-9C99-627926B6F4A4}
- ProgID

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{79848780-3218-4973-9C99-627926B6F4A4}
- VersionIndependentProgID

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{79848780-3218-4973-9C99-627926B6F4A4}
- Programmable

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{79848780-3218-4973-9C99-627926B6F4A4}
- InprocServer32

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{79848780-3218-4973-9C99-627926B6F4A4}
- TypeLib

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
- {A8954909-1F0F-41A5-A7FA-3B376D69E226}

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}
- 1.0

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0
- FLAGS

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0
- 0

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0\0
- win32

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0
- HELPDIR

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
- {CBAA871D-426D-46A6-BACE-3597E2B0CE7B}

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}
- ProxyStubClsid

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}
- ProxyStubClsid32

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}
- TypeLib

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
- {D94C46A3-F89B-45C2-962A-76E300DC5C40}

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{D94C46A3-F89B-45C2-962A-76E300DC5C40}
- ProxyStubClsid

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{D94C46A3-F89B-45C2-962A-76E300DC5C40}
- ProxyStubClsid32

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{D94C46A3-F89B-45C2-962A-76E300DC5C40}
- TypeLib

To delete the registry key this malware/grayware created:

Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
In the left panel, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft
Still in the left panel, locate and delete the key:
Bind
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows>CurrentVersion>Explorer
Still in the left panel, locate and delete the key:
Browser Helper Objects
In the left panel, double-click the following:
HKEY_CLASSES_ROOT
Still in the left panel, locate and delete the key:
whatwedo.1
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>whatwedo.1
Still in the left panel, locate and delete the key:
CLSID
Again Still in the left panel, locate and delete the key:
whatwedo
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>whatwedo
Still in the left panel, locate and delete the key:
CLSID
Again Still in the left panel, locate and delete the key:
CurVer
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>CLSID
Still in the left panel, locate and delete the key:
{79848780-3218-4973-9C99-627926B6F4A4}
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>CLSID>{79848780-3218-4973-9C99-627926B6F4A4}
Still in the left panel, locate and delete the key:
ProgID
Again Still in the left panel, locate and delete the key:
VersionIndependentProgID
Again Still in the left panel, locate and delete the key:
Programmable
Again Still in the left panel, locate and delete the key:
InprocServer32
Again Still in the left panel, locate and delete the key:
TypeLib
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>TypeLib
Still in the left panel, locate and delete the key:
{A8954909-1F0F-41A5-A7FA-3B376D69E226}
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>TypeLib>{A8954909-1F0F-41A5-A7FA-3B376D69E226}
Still in the left panel, locate and delete the key:
1.0
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>TypeLib>{A8954909-1F0F-41A5-A7FA-3B376D69E226}>1.0
Still in the left panel, locate and delete the key:
FLAGS
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>TypeLib>{A8954909-1F0F-41A5-A7FA-3B376D69E226}>1.0>0
Still in the left panel, locate and delete the key:
win32
Again Still in the left panel, locate and delete the key:
HELPDIR
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>Interface
Still in the left panel, locate and delete the key:
{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>Interface>{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}
Still in the left panel, locate and delete the key:
ProxyStubClsid
Again Still in the left panel, locate and delete the key:
ProxyStubClsid32
Again Still in the left panel, locate and delete the key:
TypeLib
Again Still in the left panel, locate and delete the key:
{D94C46A3-F89B-45C2-962A-76E300DC5C40}
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>Interface>{D94C46A3-F89B-45C2-962A-76E300DC5C40}
Still in the left panel, locate and delete the key:
ProxyStubClsid
Again Still in the left panel, locate and delete the key:
ProxyStubClsid32
Again Still in the left panel, locate and delete the key:
TypeLib
Close Registry Editor.

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\Classes\CLSID\{79848780-3218-4973-9C99-627926B6F4A4}\InprocServer32
- ThreadingModel = "Apartment"

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{CBAA871D-426D-46A6-BACE-3597E2B0CE7B}\TypeLib
- Version = "1.0"

In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{D94C46A3-F89B-45C2-962A-76E300DC5C40}\TypeLib
- Version = "1.0"

Step 5

Search and delete these files

[ Learn More ]

There may be some component 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.

%System%\eyfwin.dll
%Windows%\ios.dat
%System%\p.ico
%Desktop%\SMS TRAP.url
%Favorites%\SMS TRAP.url
%Start Menu%\SMS TRAP.url
%System%\sf.ico
%Desktop%\Cheap Software.url
%Favorites%\Cheap Software.url
%Start Menu%\Cheap Software.url
%System%\c.ico
%Desktop%\VIP Casino.url
%Favorites%\VIP Casino.url
%Start Menu%\VIP Casino.url
%System%\m.ico
%Desktop%\Cheap Pharmacy Online.url
%Favorites%\Cheap Pharmacy Online.url
%Start Menu%\Cheap Pharmacy Online.url
%System%\m3.ico
%Desktop%\MP3 Download.url
%Favorites%\MP3 Download.url
%Start Menu%\MP3 Download.url
%System%\s.ico
%Desktop%\Search Online.url
%Favorites%\Search Online.url
%Start Menu%\Search Online.url
%User Temp%\ieF6C.tmp

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_BHO.UW. 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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