Analysis by: Michael Jay Villanueva
ALIASES:

TrojanSpy:MSIL/Golroted.E (Microsoft); Trojan-Dropper.Win32.Dapato.ojtk (Kaspersky); Troj/Limitai-KQ (Sophos)

 PLATFORM:

Windows

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This spyware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size: 1,192,448 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 09 Aug 2016

Arrival Details

This spyware 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 spyware drops the following copies of itself into the affected system:

  • %User Profile%\Templates\tyughjvbn.exe -> for Windows XP
  • %Application Data%\Microsoft\Windows\Templates\tyughjvbn.exe -> for Windows 7

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Application = %User Profile%\Templates\tyughjvbn.exe
(Note: For Windows XP)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Application = %Application Data%\Microsoft\Windows\Templates\tyughjvbn.exe
(Note: For Windows 7)

Other System Modifications

This spyware modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 1

(Note: The default value data of the said registry entry is 2.)

Dropping Routine

This spyware drops the following files:

  • %Application Data%\pid.txt
  • %Application Data%\pidloc.txt
  • %User Temp%\Mail.txt
  • %User Temp%\Web.txt
  • %User Profile%\My Documents\New text document.txt -> for Windows XP
  • %User Profile%\Documents\New text document.txt -> for Windows 7

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Information Theft

This spyware gathers the following data:

  • keyboard logs
  • clipboard logs
  • Screenshot
  • Local Date and Time
  • OS Version
  • Processor Information
  • Default Browser
  • .Net version
  • Installed AV
  • Installed Firewall
  • Internal IP Address
  • External IP Address

Other Details

This spyware connects to the following URL(s) to get the affected system's IP address:

  • http://checkip.dyndns.org/

It does the following:

  • Attempts to get login credentials such as server, username and password from the following:
    • Microsoft FTP
    • FileZilla
    • FTP Commander
    • JDownloder v2.0
    • Steam
  • Attempts to get stored credential from the following:
    • Eudora
    • Gmail
    • Google Desktop
    • Group Mail Free
    • Hotmail/MSN
    • IncrediMail
    • MS Outlook
    • MS Outlook 2002/2003/2007/2010
    • Netscape Mail
    • Outlook 2013
    • Outlook 2016
    • Outlook Express
    • Thunderbird
    • Windows Live Mail
    • Windows Mail
    • Yahoo! Mail
  • Attempts to get stored info such as username, password and hostnames from the following browsers:
    • Internet Explorer
    • Firefox
    • Chrome
    • Opera
    • Safari
    • SeaMonkey
  • It sends gathered information to the following email address via smtp.mail.ru:
    • {BLOCKED}ader@mail.ru

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 12.704.02
FIRST VSAPI PATTERN DATE: 09 Aug 2016
VSAPI OPR PATTERN File: 12.705.00
VSAPI OPR PATTERN Date: 10 Aug 2016

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

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
    • Application = %User Profile%\Templates\tyughjvbn.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Application = %Application Data%\Microsoft\Windows\Templates\tyughjvbn.exe

Step 5

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\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: Hidden = 1
      To: Hidden = 2

Step 6

Search and delete these files

[ 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%\pid.txt
  • %Application Data%\pidloc.txt
  • %User Temp%\Mail.txt
  • %User Temp%\Web.txt
  • %User Profile%\My Documents\New text document.txt -> for Windows XP
  • %User Profile%\Documents\New text document.txt -> for Windows 7

Step 7

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