Analysis by: Rhena Inocencio

ALIASES:

Rogue:Win32/Winwebsec (Microsoft)

 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, Dropped by other malware

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 modifies the Internet Explorer Zone Settings.

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: 643,584 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 27 Oct 2012
Payload: Connects to URLs/IPs, Displays images

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:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

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:\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.. %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.)

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\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.)

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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{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 NT
BuildVersion = "0"

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

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Other Details

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

  • {BLOCKED}c.com
  • {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:

NOTES:

This malware runs only if the date is set before September 1, 2012 (GMT).

  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

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

Identify and terminate files detected as TROJ_FAKEAV.EHL

[ Learn More ]
  1. 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.
  2. 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • {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"

Step 5

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

Step 6

Search and delete this file

[ 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

Reset Internet security settings

[ Learn More ]

Step 8

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