TROJ_DROPPR.UTA

July 15, 2014
 Analysis by: Vincent Martin Hermosura
 ALIASES:

Trojan horse Generic36.VMR (AVG), W32/Agent.LCJK!tr (Fortinet), Trojan-Dropper.Win32.Agent.lcjk (Kaspersky), Trojan.Win32.Generic!BT (Sunbelt), TR/Drop.Agent.lcjk (Antivir),

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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 Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

09 Jul 2014

Payload:

Drops files

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 files:

  • %User Temp%\{random}.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

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
{random} = "%User Temp%\{random}.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
SampleApp

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
SampleApp\Recent File List

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
SampleApp\Settings

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.912.02

FIRST VSAPI PATTERN DATE:

09 Jul 2014

VSAPI OPR PATTERN File:

10.913.00

VSAPI OPR PATTERN Date:

09 Jul 2014

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

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
    • {random} = "%User Temp%\{random}.exe"

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
    • Local AppWizard-Generated Applications
  • In HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications
    • SampleApp
  • In HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\SampleApp
    • Recent File List
  • In HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\SampleApp
    • Settings

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_DROPPR.UTA. 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.