Analysis by: Jennifer Gumban

ALIASES:

PWS:Win32/Fareit.gen!C (Microsoft), Trojan-PSW.Win32.Tepfer.npvb (Kaspersky), W32/Kryptik.BDPK!tr (Fortinet)

 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:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It 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.

  TECHNICAL DETAILS

File Size: 115,200 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 10 Jul 2013

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It 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 file(s)/component(s):

  • %Application Data%\{Random Folder Name}\{Random File Name}.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.)

Autostart Technique

This Trojan modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Random File Name} = "%Application Data%\{Random Folder Name}\{Random File Name}.exe"

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
{Random Characters}
{Random Characters} = "{Random Hex Values}"

HKEY_CURRENT_USER\Software\Microsoft\
{Random Characters}
{Random Characters} = "{Random Strings}"

HKEY_CURRENT_USER\Software\WinRAR
{Random Hash} = "{Random Hex Values}"

HKEY_CURRENT_USER\Software\WinRAR
{Random Hash} = "{Random Hex Values}"

HKEY_CURRENT_USER\Software\WinRAR
HWID = "{Random Hex Values}"

It modifies the following registry entries:

HKEY_CURRENT_USER\Identities
Identity Ordinal = "2"

(Note: The default value data of the said registry entry is "1".)

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}ppingcarts.com/forum/viewtopic.php
  • http://{BLOCKED}ppingcarts.net/forum/viewtopic.php
  • http://{BLOCKED}tockfoodimages.com/forum/viewtopic.php
  • http://{BLOCKED}rynow.com/forum/viewtopic.php
  • http://www.{BLOCKED}k.1stpads.com/ijiK.exe
  • http://{BLOCKED}i.com/eK1q.exe
  • http://{BLOCKED}nd.rcomhost.com/WMs9Lz.exe
  • http://www.{BLOCKED}trade.co.uk/ULiC.exe

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.144.06
FIRST VSAPI PATTERN DATE: 10 Jul 2013
VSAPI OPR PATTERN File: 10.145.00
VSAPI OPR PATTERN Date: 10 Jul 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

Scan your computer with your Trend Micro product and note files detected as TROJ_RANSOM.SM05

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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.  
  • %Application Data%\{Random Folder Name}\{Random File Name}.exe

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\{Random Characters}
    • {Random Characters} = "{Random Hex Values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\{Random Characters}
    • {Random Characters} = "{Random Strings}"
  • In HKEY_CURRENT_USER\Software\WinRAR
    • {Random Hash} = "{Random Hex Values}"
  • In HKEY_CURRENT_USER\Software\WinRAR
    • {Random Hash} = "{Random Hex Values}"
  • In HKEY_CURRENT_USER\Software\WinRAR
    • HWID = "{Random Hex Values}"

Step 6

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_CURRENT_USER\Identities
    • From: Identity Ordinal = "2"
      To: Identity Ordinal = "1"

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_RANSOM.SM05. 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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