TROJ_RENOS.SMDJ

October 02, 2013
 ALIASES:

TrojanDownloader:Win32/Renos.KF (Microsoft); Packed.Generic.246, Packed.Generic.187, Trojan.FakeAV!gen (Symantec); Packed.Win32.Krap.ae (Kaspersky); Trojan.Win32.Generic!BT, Trojan-Downloader.Win32.Renos.jm (v), Trojan-Downloader.Win32.CodecPack (v) (Sunbelt); Trojan horse Downloader.Generic10.SNC (AVG)

 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:

467,254 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

02 Oct 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:

  • %Program Files%\Target Web ADS

(Note: %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).)

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
HBlock = "%Program Files%\Target Web ADS\TargetWebADSh.exe"

It registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{8152A0B9-DEB6-476e-BC67-175B19080A8A}

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\nsb1.tmp

(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.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\TargetWebADS

HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}

HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}\
InprocServer32

HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}\
ProgID

HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}\
Programmable

HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}\
TypeLib

HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}\
VersionIndependentProgID

HKEY_CLASSES_ROOT\TargetWebADS.TargetWebADS

HKEY_CLASSES_ROOT\TargetWebADS.TargetWebADS\CLSID

HKEY_CLASSES_ROOT\TargetWebADS.TargetWebADS\CurVer

HKEY_CLASSES_ROOT\TargetWebADS.TargetWebADS.1

HKEY_CLASSES_ROOT\TargetWebADS.TargetWebADS.1\CLSID

HKEY_CLASSES_ROOT\TypeLib\{DFB2E345-AD44-462d-B07A-A513718FABDB}

HKEY_CLASSES_ROOT\TypeLib\{DFB2E345-AD44-462d-B07A-A513718FABDB}\
_CHAR(0x01)_.0

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
{02092770-F6F6-4dce-BDDD-46527E098E57}

HKEY_CURRENT_USER\Software\TargetWebADS\
HBlock

HKEY_CURRENT_USER\Software\TargetWebADS\
BBlock

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}
Install = "OK"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}\InprocServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{02092770-F6F6-4dce-BDDD-46527E098E57}
DisplayName = "Target Web ADS"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{02092770-F6F6-4dce-BDDD-46527E098E57}
UninstallString = "%Program Files%\Target Web ADS\Uninstall.exe"

HKEY_CURRENT_USER\Software\TargetWebADS\
HBlock
Pt00000002 = "{random characters}"

HKEY_CURRENT_USER\Software\TargetWebADS\
HBlock
Pq00000002 = "1cebf41"

HKEY_CURRENT_USER\Software\TargetWebADS\
HBlock
Pq00000003 = "caf3872"

HKEY_CURRENT_USER\Software\TargetWebADS\
HBlock
Pq00000006 = "1"

HKEY_CURRENT_USER\Software\TargetWebADS\
BBlock
Pq6 = "0"

HKEY_CURRENT_USER\Software\TargetWebADS\
BBlock
Pq0 = "1cebf41"

HKEY_CURRENT_USER\Software\TargetWebADS\
BBlock
Pq1 = "ca4c98c"

Dropping Routine

This Trojan drops the following files:

  • %Program Files%\Target Web ADS\TargetWebADS.dll
  • %Program Files%\Target Web ADS\TargetWebADSh.exe
  • %Program Files%\Target Web ADS\TargetWebADSb.exe
  • %Program Files%\Target Web ADS\Uninstall.exe
  • %Windows%\Tasks\{7B02EF0B-A410-4938-8480-9BA26420A627}.job

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

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}repository.com/resolution.php
  • http://{BLOCKED}repository.com/borders.php
  • http://{BLOCKED}repository.com/ad_type.php

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

Close all opened browser windows

Step 4

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
    • TargetWebADS
  • In HKEY_CLASSES_ROOT\CLSID
    • {8152A0B9-DEB6-476e-BC67-175B19080A8A}
  • In HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}
    • InprocServer32
  • In HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}
    • ProgID
  • In HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}
    • Programmable
  • In HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}
    • TypeLib
  • In HKEY_CLASSES_ROOT\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}
    • VersionIndependentProgID
  • In HKEY_CLASSES_ROOT
    • TargetWebADS.TargetWebADS
  • In HKEY_CLASSES_ROOT\TargetWebADS.TargetWebADS
    • CLSID
  • In HKEY_CLASSES_ROOT\TargetWebADS.TargetWebADS
    • CurVer
  • In HKEY_CLASSES_ROOT
    • TargetWebADS.TargetWebADS.1
  • In HKEY_CLASSES_ROOT\TargetWebADS.TargetWebADS.1
    • CLSID
  • In HKEY_CLASSES_ROOT\TypeLib
    • {DFB2E345-AD44-462d-B07A-A513718FABDB}
  • In HKEY_CLASSES_ROOT\TypeLib\{DFB2E345-AD44-462d-B07A-A513718FABDB}
    • _CHAR(0x01)_.0
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • {02092770-F6F6-4dce-BDDD-46527E098E57}
  • In HKEY_CURRENT_USER\Software\TargetWebADS
    • HBlock
  • In HKEY_CURRENT_USER\Software\TargetWebADS
    • BBlock

Step 5

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
    • HBlock = "%Program Files%\Target Web ADS\TargetWebADSh.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}
    • Install = "OK"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{8152A0B9-DEB6-476e-BC67-175B19080A8A}\InprocServer32
    • ThreadingModel = "Apartment"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{02092770-F6F6-4dce-BDDD-46527E098E57}
    • DisplayName = "Target Web ADS"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{02092770-F6F6-4dce-BDDD-46527E098E57}
    • UninstallString = "%Program Files%\Target Web ADS\Uninstall.exe"
  • In HKEY_CURRENT_USER\Software\TargetWebADS\HBlock
    • Pt00000002 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\TargetWebADS\HBlock
    • Pq00000002 = "1cebf41"
  • In HKEY_CURRENT_USER\Software\TargetWebADS\HBlock
    • Pq00000003 = "caf3872"
  • In HKEY_CURRENT_USER\Software\TargetWebADS\HBlock
    • Pq00000006 = "1"
  • In HKEY_CURRENT_USER\Software\TargetWebADS\BBlock
    • Pq6 = "0"
  • In HKEY_CURRENT_USER\Software\TargetWebADS\BBlock
    • Pq0 = "1cebf41"
  • In HKEY_CURRENT_USER\Software\TargetWebADS\BBlock
    • Pq1 = "ca4c98c"

Step 6

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.
  • %Program Files%\Target Web ADS\TargetWebADS.dll
  • %Program Files%\Target Web ADS\TargetWebADSh.exe
  • %Program Files%\Target Web ADS\TargetWebADSb.exe
  • %Program Files%\Target Web ADS\Uninstall.exe
  • %Windows%\Tasks\{7B02EF0B-A410-4938-8480-9BA26420A627}.job

Step 7

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.
  • %Program Files%\Target Web ADS

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_RENOS.SMDJ. 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 9

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 Temp%\nsb1.tmp


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