ADW_BROWS


 ALIASES:

Trojan.Win32.Generic!BT (Sunbelt)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Adware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size:

1,452,222 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

19 Feb 2015

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.

Installation

This adware creates the following folders:

  • %User Temp%\is-4HHRM.tmp
  • %User Temp%\is-3AI55.tmp
  • %User Temp%\is-3AI55.tmp\_isetup
  • %Program Files%\Microsoft Data
  • %User Temp%\Folder_Temp_12-21
  • %User Temp%\Folder_Temp_12-21\adds
  • %User Temp%\Folder_Temp_12-21\js
  • %User Temp%\Folder_Temp_12-21\xml

(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.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Autostart Technique

This adware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
chrome5 = "{random characters}"

Other System Modifications

This adware deletes the following files:

  • %User Temp%\Folder_Temp_12-21/?¼?H?

(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.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Google\Update

HKEY_CURRENT_USER\SOFTWARE\Policies\
Google\Update

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows\AppCompat

HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft\Windows\AppCompat

HKEY_CURRENT_USER\SOFTWARE\GTN_STF

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
Inno Setup: Setup Version = "5.5.3 (u)"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
Inno Setup: App Path = "%Program Files%\Microsoft Data"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
InstallLocation = "%Program Files%\Microsoft Data"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
Inno Setup: Icon Group = "(Default)"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
Inno Setup: User = "Wilbert"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
Inno Setup: Language = "default"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
DisplayName = "WebSecurity Extension version 16.40"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
UninstallString = "%Program Files%\Microsoft Data\unins000.exe "

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
QuietUninstallString = "%Program Files%\Microsoft Data\unins000.exe /SILENT"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
DisplayVersion = "16.40"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
NoModify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
NoRepair = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
InstallDate = "20150210"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
MajorVersion = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1
MinorVersion = "28"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Google\Update
UpdateDefault = "0"

HKEY_CURRENT_USER\Software\Policies\
Google\Update
UpdateDefault = "0"

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows\AppCompat
DisablePCA = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\AppCompat
DisablePCA = "1"

HKEY_CURRENT_USER\Software\GTN_STF
uniID = "1423564161757"

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
WebSecurity Extension_is1

Dropping Routine

This adware drops the following files:

  • %User Temp%\is-4hhrm.tmp\{malware file name}.tmp
  • %User Temp%\is-3AI55.tmp\_isetup\_shfoldr.dll
  • %Program Files%\Microsoft Data\unins000.dat
  • %Program Files%\Microsoft Data\is-LEAGH.tmp
  • %Program Files%\Microsoft Data\is-MLVCL.tmp
  • %Program Files%\Microsoft Data\is-GFN9D.tmp
  • %Program Files%\Microsoft Data\is-NA4AE.tmp
  • %Program Files%\Microsoft Data\is-H7P5U.tmp
  • %Program Files%\Microsoft Data\is-NQBUI.tmp
  • %User Temp%\Folder_Temp_12-21\uni_id_exist.glog
  • %User Temp%\Folder_Temp_12-21\log_chrome.glog
  • %User Profile%\Application Data\smw_inst
  • %User Temp%\Folder_Temp_12-21\adds\xx.crx
  • %User Temp%\Folder_Temp_12-21\adds\xx.oex
  • %User Temp%\Folder_Temp_12-21\adds\xx.xpi
  • %User Temp%\Folder_Temp_12-21\js\chr_pref.json
  • %User Temp%\Folder_Temp_12-21\js\ff_set.json
  • %User Temp%\Folder_Temp_12-21\xml\op_data.xml
  • %User Temp%\Folder_Temp_12-21\xml\op_wid.xml
  • %User Temp%\Folder_Temp_12-21\xml\task.xml
  • rmAds.bat
  • %User Temp%\Folder_Temp_12-21\log_opera.glog
  • %User Temp%\Folder_Temp_12-21\log_firefox.glog

(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.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other Details

This adware connects to the following possibly malicious URL:

  • {BLOCKED}.7.250

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.700

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

Restart in Safe Mode

[ Learn More ]

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_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • WebSecurity Extension_is1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google
    • Update
  • In HKEY_CURRENT_USER\SOFTWARE\Policies\Google
    • Update
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows
    • AppCompat
  • In HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows
    • AppCompat
  • In HKEY_CURRENT_USER\SOFTWARE
    • GTN_STF

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\Run
    • chrome5 = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • Inno Setup: Setup Version = "5.5.3 (u)"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • Inno Setup: App Path = "%Program Files%\Microsoft Data"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • InstallLocation = "%Program Files%\Microsoft Data"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • Inno Setup: Icon Group = "(Default)"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • Inno Setup: User = "Wilbert"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • Inno Setup: Language = "default"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • DisplayName = "WebSecurity Extension version 16.40"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • UninstallString = "%Program Files%\Microsoft Data\unins000.exe "
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • QuietUninstallString = "%Program Files%\Microsoft Data\unins000.exe /SILENT"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • DisplayVersion = "16.40"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • NoModify = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • NoRepair = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • InstallDate = "20150210"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • MajorVersion = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\WebSecurity Extension_is1
    • MinorVersion = "28"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Update
    • UpdateDefault = "0"
  • In HKEY_CURRENT_USER\Software\Policies\Google\Update
    • UpdateDefault = "0"
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\AppCompat
    • DisablePCA = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\AppCompat
    • DisablePCA = "1"
  • In HKEY_CURRENT_USER\Software\GTN_STF
    • uniID = "1423564161757"

Step 5

Search and delete these components

[ Learn More ]
There may be some components 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%\is-4hhrm.tmp\{malware file name}.tmp
  • %User Temp%\is-3AI55.tmp\_isetup\_shfoldr.dll
  • %Program Files%\Microsoft Data\unins000.dat
  • %Program Files%\Microsoft Data\is-LEAGH.tmp
  • %Program Files%\Microsoft Data\is-MLVCL.tmp
  • %Program Files%\Microsoft Data\is-GFN9D.tmp
  • %Program Files%\Microsoft Data\is-NA4AE.tmp
  • %Program Files%\Microsoft Data\is-H7P5U.tmp
  • %Program Files%\Microsoft Data\is-NQBUI.tmp
  • %User Temp%\Folder_Temp_12-21\uni_id_exist.glog
  • %User Temp%\Folder_Temp_12-21\log_chrome.glog
  • %User Profile%\Application Data\smw_inst
  • %User Temp%\Folder_Temp_12-21\adds\xx.crx
  • %User Temp%\Folder_Temp_12-21\adds\xx.oex
  • %User Temp%\Folder_Temp_12-21\adds\xx.xpi
  • %User Temp%\Folder_Temp_12-21\js\chr_pref.json
  • %User Temp%\Folder_Temp_12-21\js\ff_set.json
  • %User Temp%\Folder_Temp_12-21\xml\op_data.xml
  • %User Temp%\Folder_Temp_12-21\xml\op_wid.xml
  • %User Temp%\Folder_Temp_12-21\xml\task.xml
  • rmAds.bat
  • %User Temp%\Folder_Temp_12-21\log_opera.glog
  • %User Temp%\Folder_Temp_12-21\log_firefox.glog

Step 6

Search and delete these folders

[ 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.
  • %User Temp%\is-4HHRM.tmp
  • %User Temp%\is-3AI55.tmp
  • %User Temp%\is-3AI55.tmp\_isetup
  • %Program Files%\Microsoft Data
  • %User Temp%\Folder_Temp_12-21
  • %User Temp%\Folder_Temp_12-21\adds
  • %User Temp%\Folder_Temp_12-21\js
  • %User Temp%\Folder_Temp_12-21\xml

Step 7

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

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %User Temp%\Folder_Temp_12-21/?¼?H?

Step 9

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • WebSecurity Extension_is1


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