PLATFORM:

Windows

 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.

  TECHNICAL DETAILS

File Size: 1,970,688 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 01 Sep 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 creates the following folders:

  • %Start Menu%\Programs\Zentom System Guard

(Note: %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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 Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{malware file name} = "{malware path and file name} "

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
Zentom System Guard

It adds the following registry entries:

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
datarl1 = "KRoAGVdOQwQOHhMhHE0dAQ=="

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
datarl2 = "KRoAGVdOQxEKHxxwW00dAQ=="

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
install_time = "8/5/2015 5:38:41 AM"

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
database_version = "249"

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
virus_signatures = "61258"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
Zentom System Guard
DisplayIcon = "{malware path and file name},0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
Zentom System Guard
DisplayName = "Zentom System Guard"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
Zentom System Guard
UninstallString = "{malware path and file name} /uninstall"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
Zentom System Guard
NoModify = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
Zentom System Guard
NoRepair = "1"

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
inst = "ok"

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
coid = "NDA0ODQzMjAxODc3NDg4HkN0w0TEQz"

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
affid = "7070010200"

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
url_update_time = "8/5/2015 5:38:41 AM"

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
nsupdlf = "1"

HKEY_CURRENT_USER\Software\ZentomSystemGuard\
Zentom System Guard
nsa = "1"

Dropping Routine

This Trojan drops the following files:

  • %System Root%\enemies-names.txt
  • %System Root%\local.ini
  • %System Root%\hookdll.dll
  • %User Startup%\Zentom System Guard.lnk
  • %Desktop%\Zentom System Guard.lnk
  • %Start Menu%\Zentom System Guard.lnk
  • %Start Menu%\Programs\Zentom System Guard\Zentom System Guard.lnk
  • %Start Menu%\Programs\Zentom System Guard\Uninstall.lnk
  • %User Profile%\Quick Launch\Zentom System Guard.lnk

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop 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.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.750

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 key

[ 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\Uninstall
    • Zentom System Guard

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
    • {malware file name} = "{malware path and file name} "
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • datarl1 = "KRoAGVdOQwQOHhMhHE0dAQ=="
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • datarl2 = "KRoAGVdOQxEKHxxwW00dAQ=="
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • install_time = "8/5/2015 5:38:41 AM"
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • database_version = "249"
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • virus_signatures = "61258"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\Zentom System Guard
    • DisplayIcon = "{malware path and file name},0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\Zentom System Guard
    • DisplayName = "Zentom System Guard"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\Zentom System Guard
    • UninstallString = "{malware path and file name} /uninstall"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\Zentom System Guard
    • NoModify = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\Zentom System Guard
    • NoRepair = "1"
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • inst = "ok"
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • coid = "NDA0ODQzMjAxODc3NDg4HkN0w0TEQz"
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • affid = "7070010200"
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • url_update_time = "8/5/2015 5:38:41 AM"
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • nsupdlf = "1"
  • In HKEY_CURRENT_USER\Software\ZentomSystemGuard\Zentom System Guard
    • nsa = "1"

Step 5

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %System Root%\enemies-names.txt
  • %System Root%\local.ini
  • %System Root%\hookdll.dll
  • %User Startup%\Zentom System Guard.lnk
  • %Desktop%\Zentom System Guard.lnk
  • %Start Menu%\Zentom System Guard.lnk
  • %Start Menu%\Programs\Zentom System Guard\Zentom System Guard.lnk
  • %Start Menu%\Programs\Zentom System Guard\Uninstall.lnk
  • %User Profile%\Quick Launch\Zentom System Guard.lnk

Step 6

Search and delete this folder

[ 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.
  • %Start Menu%\Programs\Zentom System Guard

Step 7

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