Modified by: Rika Joi Gregorio
ALIASES:

Infostealer.Limitail(Symantec)

 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: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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

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: 1,144,632 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 27 Mar 2014
Payload: Connects to URLs/IPs, Steals information, Drops files

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 component file(s):

  • %User Profile%\gwhu318b\AXbRGpn.ENA
  • %User Profile%\gwhu318b\ksKkTVQ.KLV
  • %User Profile%\gwhu318b\LzpOALh.exe
  • %User Profile%\gwhu318b\xCKwh.YXO
  • %User Temp%\logff.txt

(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.. %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.)

It drops and executes the following files:

  • %User Profile%\gwhu318b\Example.exe - non-malicious

(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.)

It adds the following processes:

  • RegSvcs.exe

It injects itself into the following processes running in the affected system's memory:

  • created RegSvcs.exe

It creates the following folders:

  • %User Profile%\gwhu318b
  • %Application Data%\Microsoft\Backups

(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
Example = "%User Profile%\gwhu318b\Example.exe"

It drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\RegSvcs.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

Information Theft

This spyware gathers the following data:

  • Browser Cache Usernames/Password (Chrome, IE,Safari,Opera)
  • Internet Download Manager Credentials
  • Smart FTP & Core FTP Credentials
  • Computer Information (Computer Name, IP Address, Diskspace, OS version/platform, Firewall Installed, AV Installed)
  • Clipboard Data (w/ Window Title)
  • Keystroke (w/ Window Title)

Other Details

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

  • http://www.{BLOCKED}ip.ru/en-EN/index.php

NOTES:

It will then connect to the following URL to send the stolen formation in an email format:

  • {BLOCKED}essmail.{BLOCKED}l.com

  SOLUTION

Minimum Scan Engine: 9.700

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 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
    • Example = "%User Profile%\gwhu318b\Example.exe"

Step 4

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.
  • %User Profile%\gwhu318b
  • %Application Data%\Microsoft\Backups

Step 5

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 Profile%\gwhu318b\Example.exe
  • %User Startup%\RegSvcs.exe
  • %User Temp%\logff.txt

Step 6

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