TROJ_FAKEAV.BUTH

 Analysis by: Nikko Tamana

 ALIASES:

Rogue:Win32/FakeDef (Microsoft), Win32/Adware.PCDefenderPlus.A (NOD32)

 PLATFORM:

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

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware


This Trojan may be dropped by other malware.

It does not have any propagation routine.

It does not have any backdoor routine.

When users agree to buy the software, it connects to a certain URL. It displays fake alerts that warn users of infection. It also displays fake scanning results of the affected system. It then asks for users to purchase it once scanning is completed. If users decide to purchase the rogue product, users are directed to a website asking for sensitive information, such as credit card numbers. It displays a window where users can purchase this fake antivirus program.

  TECHNICAL DETAILS

File Size:

1,183,712 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

18 Jan 2013

Payload:

Terminates processes, Connects to URLs/IPs, Displays fake alerts

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_DLOADR.BUTH

Installation

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

  • {All Users' Profile}\Application Data\pcdfdata\app.ico
  • {All Users' Profile}\Application Data\pcdfdata\defs.bin - contains downloaded malware information
  • {All Users' Profile}\Application Data\pcdfdata\support.ico
  • {All Users' Profile}\Application Data\pcdfdata\uninst.ico
  • %Desktop%\Security Defender.lnk
  • %Start Menu%\Programs\Security Defender\Remove Security Defender.lnk
  • %Start Menu%\Programs\Security Defender\Security Defender Help and Support.lnk
  • %Start Menu%\Programs\Security Defender\Security Defender.lnk

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

It creates the following folders:

  • %Start Menu%\Programs\Security Defender

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

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

  • Global\wdshield

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
pcdfsvc = "{All Users' Profile}\Application Data\pcdfdata\{TROJ_DLOADR.BUTH file name}.exe /min"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
pcdfdata

HKEY_CLASSES_ROOT\.exe\DefaultIcon

HKEY_CLASSES_ROOT\.exe\shell

HKEY_CLASSES_ROOT\.exe\shell\
open

HKEY_CLASSES_ROOT\.exe\shell\
open\command

HKEY_CLASSES_ROOT\.exe\shell\
runas

HKEY_CLASSES_ROOT\.exe\shell\
runas\command

HKEY_CURRENT_USER\Software\Classes\
.exe

HKEY_CURRENT_USER\Software\Classes\
.exe\shell

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\open

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\open\
command

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\runas

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\runas\
command

It adds the following registry entries:

HKEY_CLASSES_ROOT\.exe\DefaultIcon
{Default} = "%1"

HKEY_CLASSES_ROOT\.exe\shell\
open\command
{Default} = ""{All Users' Profile}\Application Data\pcdfdata\{TROJ_DLOADR.BUTH file name}.exe" /ex "%1" %*"

HKEY_CLASSES_ROOT\.exe\shell\
open\command
IsolatedCommand = ""%1" %*"

HKEY_CLASSES_ROOT\.exe\shell\
runas\command
{Default} = ""%1" %*"

HKEY_CLASSES_ROOT\.exe\shell\
runas\command
IsolatedCommand = ""%1" %*"

HKEY_CURRENT_USER\Software\Classes\
.exe
{Default} = "4g"

HKEY_CURRENT_USER\Software\Classes\
.exe Content
Type = "application/x-m"

HKEY_CURRENT_USER\Software\Classes\
.exe\DefaultIcon
{Default} = "%1"

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\open\
command
{Default} = ""{All Users' Profile}\Application Data\pcdfdata\{TROJ_DLOADR.BUTH file name}.exe" /ex "%1" %*"

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\open\
command
IsolatedCommand = ""%1" %*"

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\runas\
command
{Default} = ""%1" %*"

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\runas\
command
IsolatedCommand = ""%1" %*"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
pcdfdata
DisplayName = "Security Defender"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
pcdfdata
InstallLocation = "{All Users' Profile}\Application Data\pcdfdata"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
pcdfdata
UninstallString = "{All Users' Profile}\Application Data\pcdfdata\{TROJ_DLOADR.BUTH file name}.exe /tout"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
pcdfdata
DisplayIcon = "{All Users' Profile}\Application Data\pcdfdata\{TROJ_DLOADR.BUTH file name}.exe,0"

It modifies the following registry entries:

HKEY_CLASSES_ROOT\.exe
{Default} = "4g"

(Note: The default value data of the said registry entry is exefile.)

HKEY_CLASSES_ROOT\.exe
Content Type = "application/x-m"

(Note: The default value data of the said registry entry is application/x-msdownload.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Rogue Antivirus Routine

This Trojan displays the following fake alerts:

When users agree to buy the software, it connects to the following URL to continue the purchase:

  • https://{BLOCKED}.{BLOCKED}ng.com/billing/key/?uid={value}

It displays fake alerts that warn users of infection. It also displays fake scanning results of the affected system. It then asks for users to purchase it once scanning is completed. If users decide to purchase the rogue product, users are directed to the following website asking for sensitive information, such as credit card numbers:

  • https://{BLOCKED}.{BLOCKED}ng.com/html/billing/?uid={value}

The following window is displayed for users to purchase the fake antivirus program:

It displays the following window and pretends to scan the system:

NOTES:

This Trojan connects to the following URL to let the remote user know that the download was successful:

  • http://{BLOCKED}ologyipadinitiating.org/api/ping?stage={number}&uid={random values}

It connects to the following URL to let the remote user know that TROJ_FAKEAV.BUTH has been successfully executed:

  • http://{BLOCKED}ologyipadinitiating.org/postload2/?uid={random values}

It connects to the URL to get updated list of virus information:

  • http://{BLOCKED}ologyipadinitiating.org/html/viruslist/?uid={random values}

However, the said sites are inaccessible during time of analysis.

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.664.01

FIRST VSAPI PATTERN DATE:

18 Jan 2013

VSAPI OPR PATTERN File:

9.665.00

VSAPI OPR PATTERN Date:

19 Jan 2013

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

Remove the malware/grayware file that dropped/downloaded TROJ_FAKEAV.BUTH

  • TROJ_DLOADR.BUTH

Step 3

Scan your computer with your Trend Micro product and note files detected as TROJ_FAKEAV.BUTH

Step 4

Restart in Safe Mode

[ Learn More ]

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
    • pcdfsvc = "{All Users' Profile}\Application Data\pcdfdata\{TROJ_DLOADR.BUTH file name}.exe /min"

Step 6

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
    • pcdfdata
  • In HKEY_CLASSES_ROOT\.exe
    • DefaultIcon
  • In HKEY_CLASSES_ROOT\.exe
    • shell
  • In HKEY_CURRENT_USER\Software\Classes
    • .exe

Step 7

Restore this modified 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_CLASSES_ROOT\.exe
    • From: {Default} = "4g"
      To: {Default} = "exefile"
  • In HKEY_CLASSES_ROOT\.exe
    • From: Content Type = "application/x-m"
      To: Content Type = "application/x-msdownload"

Step 8

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.
  • %Desktop%\Security Defender.lnk

Step 9

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.
  • {All Users' Profile}\Application Data\pcdfdata
  • %Start Menu%\Programs\Security Defender

Step 10

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