Analysis by: Mark Joseph Manahan
ALIASES:

Troj/VBDrop-AS (Sophos) ,Trojan horse Generic35.AXFQ (AVG) ,W32/Dorkbot.BAAr (Fortinet) ,Trojan.Win32.Inject (Ikarus) ,Trojan.Win32.Inject.gyju (Kaspersky) ,Trojan.Dropper (Symantec) ,Trojan.Win32.GenericT (Sunbelt)

 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:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This Trojan may be downloaded by other malware/grayware from remote sites.

It connects to certain websites to send and receive information. It creates an event.

  TECHNICAL DETAILS

File Size: 103,374 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 10 Jan 2014
Payload: Steals information, Connects to URLs/IPs

Arrival Details

This Trojan may be downloaded by the following malware/grayware from remote sites:

  • TSPY_FAREIT.AUN

Installation

This Trojan drops the following files:

  • %User Temp%\setup.dat
  • %User Temp%\a.dat
  • %Application Data%\Mozilla\Firefox\Profiles\4wwmjcqo.default\extensions.sqlite
  • %Application Data%\Mozilla\Firefox\Profiles\4wwmjcqo.default\extensions\{A9E3A5E6-A75E-B689-2181-696FC74540D3\chrome.manifest
  • %Application Data%\Mozilla\Firefox\Profiles\4wwmjcqo.default\extensions\{A9E3A5E6-A75E-B689-2181-696FC74540D3\install.rdf
  • %Application Data%\Mozilla\Firefox\Profiles\4wwmjcqo.default\extensions.sqlite\{A9E3A5E6-A75E-B689-2181-696FC74540D3\components\RMGetLicenseClass.js - detected as JS_MIUREF.C

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %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 and executes the following files:

  • %User Temp%\gjbjojht.exe - detected as TROJ_MIUREF.AI

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

It adds the following processes:

  • iexplore.exe

It creates the following folders:

  • %Application Data%\Mozilla\Firefox\Profiles\4wwmjcqo.default\extensions\{A9E3A5E6-A75E-B689-2181-696FC74540D3
  • %Application Data%\Mozilla\Firefox\Profiles\4wwmjcqo.default\extensions\{A9E3A5E6-A75E-B689-2181-696FC74540D3\components

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
{GUID} = "%User Temp%\gjbjojht.exe"

Information Theft

This Trojan gathers the following data:

  • Computer name / username
  • OS version
  • Browser information

Other Details

Based on analysis of the codes, it has the following capabilities:

  • Install Browser plugins (it may do this monitor browser activites, display popup ads or execute arbitrary scripts)

It connects to the following website to send and receive information:

  • http://{BLOCKED}.{BLOCKED}.80.139/{value}
  • http://{BLOCKED}.{BLOCKED}.212.49/{value}

It creates the following event(s):

  • {Computer Name}{Fullpath and Filename} special characters replaced with '_'

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.532.03
FIRST VSAPI PATTERN DATE: 10 Jan 2014
VSAPI OPR PATTERN File: 10.533.00
VSAPI OPR PATTERN Date: 11 Jan 2014

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 malware/grayware files dropped/downloaded by TROJ_MIUREF.C

    • JS_MIUREF.C
    • TROJ_MIUREF.AI

Step 3

Remove the malware/grayware file that dropped/downloaded TROJ_MIUREF.C

     
    • TSPY_FAREIT.AUN

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\RunOnce
    • {GUID} = "%User Temp%\gjbjojht.exe"

Step 6

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.
  • %Application Data%\Mozilla\Firefox\Profiles\4wwmjcqo.default\extensions\{A9E3A5E6-A75E-B689-2181-696FC74540D3

Step 7

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.
  • %User Temp%\setup.dat
  • %User Temp%\a.dat

Step 8

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


Did this description help? Tell us how we did.