TROJ_FAKEAV.JA

October 09, 2012
 Analysis by: Abraham Latimer Camba
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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 connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats.

  TECHNICAL DETAILS

File Size:

381,952 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

24 Mar 2012

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%\{random name}.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\{malware filename}\
DEBUG
Trace Level = ""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\{random name}\
DEBUG
Trace Level = ""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\{malware filename}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\{random name}

Download Routine

This Trojan connects to the following malicious URLs:

  • http://{BLOCKED}.{BLOCKED}.156.53/payform/?k=N0VXUURTHUIJUhZDVQVGFFZcQFtVdWNodGNhcEBGUV1FVgQTTVFcRwEHQhAHUEFR
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/?k=N1NWTV9AHVcfUwpYRgVTAldAW0hVY2J0b3BhZVVQUEFeRQQGW1BAXBIHVwYGTFpC
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/30day.jpg
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/bg.gif
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/box.jpg
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/cards.gif
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/checked.gif
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/corners_bot_l.gif
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/corners_bot_r.gif
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/corners_top_l.gif
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/corners_top_r.gif
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/cvv_back.png
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/page_progressbar.gif
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/sm_er.gif
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/submit.png
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/img/win/unchecked.gif
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/js/jquery.js
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/js/payform3.js
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/style/reset-min.css
  • http://{BLOCKED}.{BLOCKED}.156.53/payform/style/style.css
  • http://{BLOCKED}.{BLOCKED}.156.76/cb_soft.php?q=NlpDTFtXHlgLRBVRHFoJRRVVX19GTVMZU1dHC1paUhRqd3VrZ2JAQw9RA19DQVNTUllFQFpSBwlPR19UAAxFEA9fV1gJRQ%3D%3D

  SOLUTION

Minimum Scan Engine:

9.200

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Scan your computer with your Trend Micro product and note files detected as TROJ_FAKEAV.JA

Step 3

Identify and terminate files detected as TROJ_FAKEAV.JA

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process
    • {malware filename}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process
    • {random name}

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEAV.JA. 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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