Analysis by: David John Agni
ALIASES:

Trojan:Win64/Fleercivet.A (Microsoft), Trojan.Win64.Fleercivet (Ikarus)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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 opens a hidden Internet Explorer window.

  TECHNICAL DETAILS

File Size: 92,160 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 14 Feb 2015

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.

Installation

This Trojan drops the following copies of itself into the affected system and executes them:

  • %Application Data%\FrameworkUpdate\GoogleUpdate.exe

(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.)

It drops the following component file(s):

  • %ProgramData%\@system.temp
  • %User Temp%\{Random Filename}.tmp
  • %ProgramData%\@system3.att

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in 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.)

It creates the following folders:

  • %Application Data%\FrameworkUpdate

(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.)

It is injected into the following processes running in memory:

  • iexplore.exe
  • chrome.exe
  • firefox.exe
  • explorer.exe

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
GoogleUpdate = "%Application Data%\FrameworkUpdate\GoogleUpdate.exe"

Backdoor Routine

This Trojan connects to the following URL(s) to send and receive commands from a remote malicious user:

  • {BLOCKED}6.{BLOCKED}2.38.72
  • {BLOCKED}5.{BLOCKED}1.73.249
  • {BLOCKED}0.{BLOCKED}3.35.152
  • http://{BLOCKED}archresults.com/casino.php?params=9kwXw9wr5uUuTXcEXeErwXA8rqoFYQ3%2FivcI6mjHX5sUIVQ75Hr6KKv0FE6z7VtZOIuWYWzrRdq9e0MFc4mgkHksu3IMGGk%2F79BfD4QQKwFiWDvJ2XekFcSJGl2iwwlYW7xXu9cQTLvSfCX%2FAkh8UtPfNP%2B%2FH0WEbMuVy38gjCQ%3D
  • http://{BLOCKED}archresults.com/?aff=7581&saff=9191

Process Termination

This Trojan terminates the following processes if found running in the affected system's memory:

  • ctfmon.exe

Other Details

This Trojan opens a hidden Internet Explorer window.

NOTES:

It checks the affected system's geographic location by accessing the following URL:

  • http://www.telize.com/geoip

  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

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
    • GoogleUpdate = "%Application Data%\FrameworkUpdate\GoogleUpdate.exe"

Step 5

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%\FrameworkUpdate\

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%\FrameworkUpdate\GoogleUpdate.exe  -  Copy
  • %ProgramData%\@system3.att - encrypted URL
  • %ProgramData%\@system.temp
  • %User Temp%\{Random Filename}.tmp

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ64_FLEERCIVET.A. 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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