ALIASES:

TrojanDownloader:Win32/Renos.PG (Microsoft); Downloader-CEW.ba (McAfee); Downloader (Symantec); Trojan.Win32.Jorik.Skor.bqr (Kaspersky); virtool.win32.obfuscator.da!e (v) (Sunbelt); Trojan.Generic.5983655 (FSecure)

 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:

  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: 237,056 bytes
File Type: EXE
Initial Samples Received Date: 01 Oct 2011

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:

  • {malware path and file name}.exe

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\SNJQ66R8MU

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\_CHAR(0x03)_

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Health\{C6580269-4851-41D8-ADBC-8C2DA68FCEC1}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
SNJQ66R8MU = "{malware path and file name}.exe"

HKEY_CURRENT_USER\Software\SNJQ66R8MU
VtuH = "xC7aKZ+O6wyPlq1krRM4sG7m2LFGsYtHjHOagBf10Uk/n4gL8s8xs9LeD5KQVh3/j+XFa0mnvQ=="

HKEY_CURRENT_USER\Software\SNJQ66R8MU
VtuS = "7SDUIc7NyUn+3scc1kYSu3q03Ypcrrs91Uiwuz65qx9Nk5xk/cwysdaVeIiwR0SEi7WoDWq93ivkK298QjAhKyFXr6IFUaa1ckpl/GxKOu3AcsqayrFNxHEr+lJFj1LvlIwiUDTQg25XinoX3slUXmrIkTzgIpdtHiHpU/MsOCmfU9i5+pXDu9UR7p420oCQL2ZlZuz7+v9Ij4/uVb22OrOI16VL4YzYmTMo758Gv1LTb4fFLiaNtaUpnz2lSjaQC2kYIR/DuAGYGSt88tSeQKuNw8JSGAgl9ZBFcFQy7GtMx1xW4hX37noQgplvxinKuhQg5wwnHs5bp0kesdcUozPi1ZgRJQY1cetrUAB9TtV2MkeVDyhGxd970+rIfDNV2ckEBnyuIarcTu+azvkmMlU7LIA3ceAEXvDHRLk="

HKEY_CURRENT_USER\Software\SNJQ66R8MU
VpiH = 1cc89

HKEY_CURRENT_USER\Software\SNJQ66R8MU
VpiB = 5b92b91

HKEY_CURRENT_USER\Software\SNJQ66R8MU
Vpi0 = 1

Dropping Routine

This Trojan drops the following files:

  • %Windows%\Tasks\{22116563-108C-42c0-A7CE-60161B75E508}.job

(Note: %Windows% is the Windows folder, which is usually C:\Windows.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}ers.php

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.200

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 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
    • SNJQ66R8MU
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones
    • _CHAR(0x03)_
  • In HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Health
    • {C6580269-4851-41D8-ADBC-8C2DA68FCEC1}

Step 3

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
    • SNJQ66R8MU="{malware path and file name}.exe"
  • In HKEY_CURRENT_USER\Software\SNJQ66R8MU
    • VtuH="xC7aKZ+O6wyPlq1krRM4sG7m2LFGsYtHjHOagBf10Uk/n4gL8s8xs9LeD5KQVh3/j+XFa0mnvQ=="
  • In HKEY_CURRENT_USER\Software\SNJQ66R8MU
    • VtuS="7SDUIc7NyUn+3scc1kYSu3q03Ypcrrs91Uiwuz65qx9Nk5xk/cwysdaVeIiwR0SEi7WoDWq93ivkK298QjAhKyFXr6IFUaa1ckpl/GxKOu3AcsqayrFNxHEr+lJFj1LvlIwiUDTQg25XinoX3slUXmrIkTzgIpdtHiHpU/MsOCmfU9i5+pXDu9UR7p420oCQL2ZlZuz7+v9Ij4/uVb22OrOI16VL4YzYmTMo758Gv1LTb4fFLiaNtaUpnz2lSjaQC2kYIR/DuAGYGSt88tSeQKuNw8JSGAgl9ZBFcFQy7GtMx1xW4hX37noQgplvxinKuhQg5wwnHs5bp0kesdcUozPi1ZgRJQY1cetrUAB9TtV2MkeVDyhGxd970+rIfDNV2ckEBnyuIarcTu+azvkmMlU7LIA3ceAEXvDHRLk="
  • In HKEY_CURRENT_USER\Software\SNJQ66R8MU
    • VpiH=1cc89
  • In HKEY_CURRENT_USER\Software\SNJQ66R8MU
    • VpiB=5b92b91
  • In HKEY_CURRENT_USER\Software\SNJQ66R8MU
    • Vpi0=1

Step 4

Search and delete this file

[ Learn More ]
There may be some files 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. %Windows%\Tasks\{22116563-108C-42c0-A7CE-60161B75E508}.job

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEAV.SM86. 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.