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TROJ_LAOSHEN.F

October 10, 2012
 ALIASES:

Trojan:Win32/Laoshen.B (Microsoft); Laoren (McAfee); Trojan Horse (Symantec); PAK:UPX, Trojan.Win32.Laoshen.b, Trojan.Win32.Laoshen.b (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Laoshen.B (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: 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:

15,824 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

21 Sep 2012

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.

Other System Modifications

This Trojan deletes the following files:

  • %Windows%\SYSBCKUP\rb000.cab
  • %Windows%\SYSBCKUP\rb001.cab
  • %Windows%\SYSBCKUP\rb002.cab
  • %Windows%\SYSBCKUP\rb003.cab
  • %Windows%\SYSBCKUP\rb004.cab
  • %Windows%\SYSBCKUP\rb005.cab
  • %Windows%\SYSBCKUP\rb006.cab

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

It adds the following registry keys:

HKEY_CLASSES_ROOT\Laorenshen

HKEY_CLASSES_ROOT\LaoshenMp3

HKEY_CLASSES_ROOT\LaoshenRm

HKEY_CLASSES_ROOT\.RM

HKEY_CLASSES_ROOT\LaoshenDAT

HKEY_CLASSES_ROOT\LaoshenAVI

HKEY_CLASSES_ROOT\LaoshenTXT

HKEY_CLASSES_ROOT\LaoshenCOM

HKEY_CLASSES_ROOT\LaoshenZIP

HKEY_CLASSES_ROOT\LaoshenRAR

HKEY_CLASSES_ROOT\.RAR

HKEY_CLASSES_ROOT\LaoshenREG

HKEY_CLASSES_ROOT\LaoshenDLL

HKEY_CLASSES_ROOT\LaoshenBAT

HKEY_CLASSES_ROOT\LaoshenSYS

HKEY_CLASSES_ROOT\LaoshenINI

HKEY_CLASSES_ROOT\LaoshenLOG

HKEY_CLASSES_ROOT\LaoshenBIN

HKEY_CLASSES_ROOT\LaoshenDOC

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Laorenshen
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Laorenshen
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenMp3
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenMp3
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenRm
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenRm
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenDAT
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenDAT
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenAVI
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenAVI
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenTXT
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenTXT
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenCOM
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenCOM
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenZIP
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenZIP
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenRAR
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenRAR
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenREG
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenREG
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenDLL
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenDLL
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenBAT
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenBAT
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenSYS
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenSYS
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenINI
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenINI
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenLOG
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenLOG
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenBIN
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenBIN
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenDOC
DefaultIcon = "%System Root%\Laorenshen.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
LaoshenDOC
Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

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_CLASSES_ROOT
    • Laorenshen
  • In HKEY_CLASSES_ROOT
    • LaoshenMp3
  • In HKEY_CLASSES_ROOT
    • LaoshenRm
  • In HKEY_CLASSES_ROOT
    • .RM
  • In HKEY_CLASSES_ROOT
    • LaoshenDAT
  • In HKEY_CLASSES_ROOT
    • LaoshenAVI
  • In HKEY_CLASSES_ROOT
    • LaoshenTXT
  • In HKEY_CLASSES_ROOT
    • LaoshenCOM
  • In HKEY_CLASSES_ROOT
    • LaoshenZIP
  • In HKEY_CLASSES_ROOT
    • LaoshenRAR
  • In HKEY_CLASSES_ROOT
    • .RAR
  • In HKEY_CLASSES_ROOT
    • LaoshenREG
  • In HKEY_CLASSES_ROOT
    • LaoshenDLL
  • In HKEY_CLASSES_ROOT
    • LaoshenBAT
  • In HKEY_CLASSES_ROOT
    • LaoshenSYS
  • In HKEY_CLASSES_ROOT
    • LaoshenINI
  • In HKEY_CLASSES_ROOT
    • LaoshenLOG
  • In HKEY_CLASSES_ROOT
    • LaoshenBIN
  • In HKEY_CLASSES_ROOT
    • LaoshenDOC

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_LOCAL_MACHINE\SOFTWARE\Classes\Laorenshen
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Laorenshen
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenMp3
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenMp3
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenRm
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenRm
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenDAT
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenDAT
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenAVI
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenAVI
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenTXT
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenTXT
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenCOM
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenCOM
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenZIP
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenZIP
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenRAR
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenRAR
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenREG
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenREG
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenDLL
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenDLL
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenBAT
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenBAT
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenSYS
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenSYS
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenINI
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenINI
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenLOG
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenLOG
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenBIN
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenBIN
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenDOC
    • DefaultIcon = "%System Root%\Laorenshen.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\LaoshenDOC
    • Shell\Open\Command = "%System Root%\Laorenshen.exe %1"

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_LAOSHEN.F. 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 5

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.

  • %Windows%\SYSBCKUP\rb000.cab
  • %Windows%\SYSBCKUP\rb001.cab
  • %Windows%\SYSBCKUP\rb002.cab
  • %Windows%\SYSBCKUP\rb003.cab
  • %Windows%\SYSBCKUP\rb004.cab
  • %Windows%\SYSBCKUP\rb005.cab
  • %Windows%\SYSBCKUP\rb006.cab


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