ALIASES:

TrojanDownloader:Win32/Rarcon.A (Microsoft); Generic Dropper!dxw (McAfee); Trojan.Gen (Symantec); Trojan-Dropper.Win32.Agent.exuh (Kaspersky); Trojan.Win32.Generic.pak!cobra (Sunbelt); Trojan.Generic.6121572 (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: 76,306 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 26 Nov 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.

Installation

This Trojan creates the following folders:

  • %Program Files%\FreeRapid
  • %User Profile%\Application Data\PIPI
  • %System Root%\zwok
  • %Windows%\LastGood
  • %Windows%\LastGood\INF
  • %Program Files%\FREERA~1\tmp
  • %Program Files%\FREERA~1\tmp\a.{971C5380-92A0-5A69-B3EE-C3002B33309E}

(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).. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows.)

Other System Modifications

This Trojan deletes the following files:

  • %User Profile%\Application Data\2.tmp
  • %System Root%\359679~1.AQQ
  • %System Root%\AFC9FE~1.BAT
  • %Windows%\INF\oem12.inf
  • %User Temp%\inl6.tmp
  • %User Temp%\include.ini

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows.. %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_LOCAL_MACHINE\SOFTWARE\WinRAR

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\ROOT\Certificates\
68A12DE4422589E97E1C6396FE17B5024FE0547A

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International\CpMRU

HKEY_CURRENT_USER\Software\tmp

HKEY_CLASSES_ROOT\CLSID\{971C5380-92A0-5A69-B3EE-C3002B33309E}

HKEY_CLASSES_ROOT\CLSID\{971C5380-92A0-5A69-B3EE-C3002B33309E}\
Shell\open(&H)\Command

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\WinRAR
socketmouse1 = "socketmouse1"

HKEY_LOCAL_MACHINE\SOFTWARE\WinRAR
uid = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\WinRAR
uname = "system"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\ROOT\Certificates\
68A12DE4422589E97E1C6396FE17B5024FE0547A
Blob = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International\CpMRU
Enable = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International\CpMRU
Size = "a"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International\CpMRU
InitHits = "64"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International\CpMRU
Factor = "14"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International
W2KLpk = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\International
W2KLpk = "0"

HKEY_CURRENT_USER\Software\tmp
key = "http://www.{BLOCKED}8.com/?r"

HKEY_LOCAL_MACHINE\SOFTWARE\WinRAR
hp = "{random values}"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Start Page = "http://www.{BLOCKED}8.com/?r"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd={SUB_PRD}&clcid={SUB_CLSID}&pver={SUB_PVER}&ar=home.)

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = "http://www.{BLOCKED}8.com/?r"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome.)

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\winrar_config.tmp
  • %Program Files%\FreeRapid\1.bin
  • %User Profile%\PIPI\bagua.ico
  • %User Profile%\PIPI\kankan.ico
  • %User Profile%\PIPI\meinv.ico
  • %User Profile%\PIPI\taobao.ico
  • %User Profile%\PIPI\1000tuan.ico
  • %Program Files%\FreeRapid\1.bat
  • %Program Files%\FreeRapid\2.bat
  • %Program Files%\FreeRapid\4.bat
  • %Program Files%\FreeRapid\loader.tmp
  • %System Root%\zwok\zxok.bat
  • %User Temp%\inl3.tmp
  • %Windows%\Comres.dll
  • afc9fe2f418b00a0.bat
  • %Program Files%\INTERN~1\ieframe.dll

(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.. %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).. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://kp.{BLOCKED}n.net/badbad.mp3

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

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_LOCAL_MACHINE\SOFTWARE
    • WinRAR
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates
    • 68A12DE4422589E97E1C6396FE17B5024FE0547A
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\International
    • CpMRU
  • In HKEY_CURRENT_USER\Software
    • tmp
  • In HKEY_CLASSES_ROOT\CLSID
    • {971C5380-92A0-5A69-B3EE-C3002B33309E}
  • In HKEY_CLASSES_ROOT\CLSID\{971C5380-92A0-5A69-B3EE-C3002B33309E}\Shell\open(&H)
    • Command

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\WinRAR
    • socketmouse1 = "socketmouse1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\WinRAR
    • uid = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\WinRAR
    • uname = "system"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates\68A12DE4422589E97E1C6396FE17B5024FE0547A
    • Blob = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\International\CpMRU
    • Enable = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\International\CpMRU
    • Size = "a"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\International\CpMRU
    • InitHits = "64"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\International\CpMRU
    • Factor = "14"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\International
    • W2KLpk = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\International
    • W2KLpk = "0"
  • In HKEY_CURRENT_USER\Software\tmp
    • key = "http://www.{BLOCKED}8.com/?r"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\WinRAR
    • hp = "{random values}"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
    • From: Start Page = "http://www.{BLOCKED}8.com/?r"
      To: Start Page = ""http://www.microsoft.com/isapi/redir.dll?prd={SUB_PRD}&clcid={SUB_CLSID}&pver={SUB_PVER}&ar=home""
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • From: Start Page = "http://www.{BLOCKED}8.com/?r"
      To: Start Page = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome""

Step 5

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.
  • %User Temp%\winrar_config.tmp
  • %Program Files%\FreeRapid\1.bin
  • %User Profile%\PIPI\bagua.ico
  • %User Profile%\PIPI\kankan.ico
  • %User Profile%\PIPI\meinv.ico
  • %User Profile%\PIPI\taobao.ico
  • %User Profile%\PIPI\1000tuan.ico
  • %Program Files%\FreeRapid\1.bat
  • %Program Files%\FreeRapid\2.bat
  • %Program Files%\FreeRapid\4.bat
  • %Program Files%\FreeRapid\loader.tmp
  • %System Root%\zwok\zxok.bat
  • %User Temp%\inl3.tmp
  • %Windows%\Comres.dll
  • afc9fe2f418b00a0.bat
  • %Program Files%\INTERN~1\ieframe.dll

Step 6

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.
  • %Program Files%\FreeRapid
  • %User Profile%\Application Data\PIPI
  • %System Root%\zwok
  • %Windows%\LastGood
  • %Windows%\LastGood\INF
  • %Program Files%\FREERA~1\tmp
  • %Program Files%\FREERA~1\tmp\a.{971C5380-92A0-5A69-B3EE-C3002B33309E}

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_AGKT.SMUS3. 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 8

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 Profile%\Application Data\2.tmp
  • %System Root%\359679~1.AQQ
  • %System Root%\AFC9FE~1.BAT
  • %Windows%\INF\oem12.inf
  • %User Temp%\inl6.tmp
  • %User Temp%\include.ini


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