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TROJ_DROPPE.LR

November 22, 2013
 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:

239,616 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

22 Nov 2013

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%\Arquivos de programas
  • %System Root%\Arquivos de programas\MratksK
  • %System Root%\Arquivos de programas\MratksK\NicsluG
  • %System Root%\Arquivos de programas\MratksK\UlssbaW
  • %System Root%\Arquivos de programas\MratksK\QghpqjT

(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_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
EqcxtlY = "%System Root%\Arquivos de programas\MratksK\UlssbaW\EqcxtlY.exe -Start"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\sistemanet

It adds the following registry entries:

HKEY_CURRENT_USER\Software\sistemanet
direct = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
name1 = "jfijaacjiijabojaafjaohjhi)"

HKEY_CURRENT_USER\Software\sistemanet
lugarjpg = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
dir2 = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
dir = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
lk1 = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
lk2 = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
lk3 = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
lk4 = "{random characters}"

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
    • sistemanet

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
    • EqcxtlY = "%System Root%\Arquivos de programas\MratksK\UlssbaW\EqcxtlY.exe -Start"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • direct = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • name1 = "jfijaacjiijabojaafjaohjhi)"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • lugarjpg = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • dir2 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • dir = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • lk1 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • lk2 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • lk3 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • lk4 = "{random characters}"

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.
  • %System Root%\Arquivos de programas
  • %System Root%\Arquivos de programas\MratksK
  • %System Root%\Arquivos de programas\MratksK\NicsluG
  • %System Root%\Arquivos de programas\MratksK\UlssbaW
  • %System Root%\Arquivos de programas\MratksK\QghpqjT

Step 6

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