TROJ_CUTOLOMO.A

February 06, 2014
 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.

  TECHNICAL DETAILS

File Size:

331,776 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

06 Feb 2014

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:

  • %System Root%\IntelNewz
  • %System Root%\IntelNewz\47603

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
netupdateAdb = "%User Profile%\Application Data\Smart Player Installer.exe "

Other System Modifications

This Trojan deletes the following files:

  • %User Profile%\Application Data\Smart Player Installer.exe
  • %Program Files%\Google\Update\GoogleUpdate.exe
  • %Program Files% (x86)\Google\Update\GoogleUpdate.exe
  • %System%\Tasks\GoogleUpdateTaskMachineCore
  • %System%\Tasks\GoogleUpdateTaskMachineUA

(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.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).. %System% is the Windows system folder, which is usually C:\Windows\System32.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\Reader

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Reader
RandomString = "47603"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"

HKEY_CURRENT_USER\Software\Reader
doUpdate = "1"

Dropping Routine

This Trojan drops the following files:

  • %User Profile%\Application Data\LinkList.txt
  • %System Root%\IntelNewz\47603\background.js
  • %System Root%\IntelNewz\47603\icon.png
  • %System Root%\IntelNewz\47603\jquery-1.9.1.min.js
  • %System Root%\IntelNewz\47603\manifest.json
  • %System Root%\IntelNewz\47603\script.js

(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.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://www.{BLOCKED}f.biz/ask.txt
  • http://www.{BLOCKED}f.biz/ajax/background.js
  • http://www.{BLOCKED}f.biz/ajax/icon.png
  • http://www.{BLOCKED}f.biz/ajax/jquery-1.9.1.min.js
  • http://www.{BLOCKED}f.biz/ajax/manifest.json
  • http://www.{BLOCKED}f.biz/ajax/script.js

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

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
    • Reader

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\Windows\CurrentVersion\Run
    • netupdateAdb = "%User Profile%\Application Data\Smart Player Installer.exe "
  • In HKEY_CURRENT_USER\Software\Reader
    • RandomString = "47603"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • EnableLUA = "0"
  • In HKEY_CURRENT_USER\Software\Reader
    • doUpdate = "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.
  • %User Profile%\Application Data\LinkList.txt
  • %System Root%\IntelNewz\47603\background.js
  • %System Root%\IntelNewz\47603\icon.png
  • %System Root%\IntelNewz\47603\jquery-1.9.1.min.js
  • %System Root%\IntelNewz\47603\manifest.json
  • %System Root%\IntelNewz\47603\script.js

Step 6

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.
  • %System Root%\IntelNewz
  • %System Root%\IntelNewz\47603

Step 7

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

Step 8

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %User Profile%\Application Data\Smart Player Installer.exe
  • %Program Files%\Google\Update\GoogleUpdate.exe
  • %Program Files% (x86)\Google\Update\GoogleUpdate.exe
  • %System%\Tasks\GoogleUpdateTaskMachineCore
  • %System%\Tasks\GoogleUpdateTaskMachineUA


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