Analysis by: Mark Joseph Manahan

ALIASES:

Rogue:Win32/Winwebsec (Microsoft), a variant of Win32/Kryptik.ALID trojan (Eset), Adware.CWSIEFeats (Symantec), Generic BackDoor.abd (McAfee)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This FAKEAV malware disguises itself as an antivirus specifically made for the Windows 8 operating system. This particular FAKEAV variant was seen in October 2012, which is the same month Windows 8 was released to the public.

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.

It connects to certain websites to send and receive information.

It displays a window where users can purchase this fake antivirus program.

  TECHNICAL DETAILS

File Size: 611,328 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 27 Oct 2012
Payload: Connects to URLs/IPs, Displays message/message boxes

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.

Installation

This Trojan drops the following copies of itself into the affected system and executes them:

  • %Application Data%\{random}.exe

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

It drops the following files:

  • %Desktop%\Buy Win 8 Security System.lnk
  • %Start Menu\Programs\Win 8 Security System\Buy Win 8 Security System.lnk
  • %Start Menu\Programs\Win 8 Security System\Launch Win 8 Security System.lnk
  • %System%\drivers\{random 2}.sys

(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.. %System% is the Windows system folder, which is usually C:\Windows\System32.)

It creates the following folders:

  • %Start Menu%\Programs\Win 8 Security System

(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.)

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
{random}.exe = "%Application Data%\{random}.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
ZoneMap\Ranges\Range1

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random 3}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random 2}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\ LEGACY_{random 2}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
GlobalUserOffline = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
ZoneMap\Ranges\Range1
* = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
ZoneMap\Ranges\Range1
:Range = "127.0.0.1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT
BuildVersion = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT
BuildNumber = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random 3}\
0000
DeviceDesc = "{random}.exe"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random 2}\
0000
Service = "random 2"

Other Details

This Trojan connects to the following website to send and receive information:

  • {BLOCKED}t.com

Rogue Antivirus Routine

This Trojan displays the following fake alerts:

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

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

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.490.01
FIRST VSAPI PATTERN DATE: 27 Oct 2012
VSAPI OPR PATTERN File: 9.491.00
VSAPI OPR PATTERN Date: 28 Oct 2012

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

Identify and terminate files detected as TROJ_FAKEAV.SMW8

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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\Windows\CurrentVersion\Internet Settings\ZoneMap\Ranges
    • Range1
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root
    • LEGACY_{random 3}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • {random 2}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root
    • LEGACY_{random 2}

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • GlobalUserOffline = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows NT
    • BuildVersion = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows NT
    • BuildNumber = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {random}.exe = "%Application Data%\{random}.exe"

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.
  • %Start Menu%\Programs\Win 8 Security System

Step 6

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.
  • %Desktop%\Buy Win 8 Security System.lnk
  • %Start Menu\Programs\Win 8 Security System\Buy Win 8 Security System.lnk
  • %Start Menu\Programs\Win 8 Security System\Launch Win 8 Security System.lnk
  • %System%\drivers\{random 2}.sys

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_FAKEAV.SMW8. 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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