Analysis by: Rika Joi Gregorio

ALIASES:

Rogue:Win32/FakeRean(Microsoft), a variant of Win32/Kryptik.BCFU trojan(Eset)

 PLATFORM:

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

 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 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 does not have any propagation routine.

It does not have any backdoor routine.

It does not have any downloading capability.

When users agree to buy the software, it connects to a certain URL. It displays a window where users can purchase this fake antivirus program.

  TECHNICAL DETAILS

File Size: 844,800 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 29 May 2013
Payload: Connects to URLs/IPs, Terminates processes, 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.

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
Internet Security = "{Malware Path and File Name}.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\{random value}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\{random value}
FRun = "0"

HKEY_CURRENT_USER\Software\{random value}
O`ld = "Houdsodu!Rdbtshux"

HKEY_CURRENT_USER\Software\{random value}
Q`ui = "{random}"

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan does not have any downloading capability.

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:

  • http://{BLOCKED}rtal360.com/404.php?id=105
  • http://{BLOCKED}echeck24.com/activate/activate.php
  • http://{BLOCKED}reinternational.com/support.php
  • http://{BLOCKED}tyserviceauto.com/buynow.php?bid=105
  • http://{BLOCKED}tyhelpsupport.com/open.php
  • http://{BLOCKED}tyserviceauto.com/support.html

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:

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.948.02
FIRST VSAPI PATTERN DATE: 29 May 2013
VSAPI OPR PATTERN File: 9.949.00
VSAPI OPR PATTERN Date: 30 May 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

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_CURRENT_USER\Software
    • {random value}

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\Run
    • Internet Security = "{Malware Path and File Name}.exe"

Step 5

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