BKDR_MORIX.POR


 ALIASES:

Trojan-Spy.Win32.Agent.cbot (Kaspersky), Backdoor:Win32/Morix.B (Microsoft), Win32/Farfli.KA trojan NOD32)

 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:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It modifies the Internet Explorer Zone Settings.

  TECHNICAL DETAILS

File Size:

154,112 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

07 Jun 2013

Arrival Details

This backdoor 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 backdoor drops the following copies of itself into the affected system:

  • %Windows%\5D6B8EB5\svchsot.exe

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

It creates the following folders:

  • %Windows%\5D6B8EB5

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

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
5D6B8EB5 = "%Windows%\5D6B8EB5\svchsot.exe"

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
rdchelp = "%Program Files%\Common Files\xkaoh.exe"

Other System Modifications

This backdoor adds the following registry keys:

HKEY_LOCAL_MACHINE\System\ControlSet001\
Control\MediaResources\msvideo

HKEY_LOCAL_MACHINE\System\InfoTime

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows\System
DisableCMD = "0"

HKEY_LOCAL_MACHINE\SYSTEM\InfoTime
InfoTime = "{date}"

Web Browser Home Page and Search Page Modification

This backdoor modifies the Internet Explorer Zone Settings.

Dropping Routine

This backdoor drops the following files:

  • %Program Files%\Common Files\xkaoh.exe
  • {malware path}\xkaoh.exe
  • %System%\drivers\etc\host.ics
  • {malware path}\{malware file name}-up.txt

(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).. %System% is the Windows system folder, which is usually C:\Windows\System32.)

Download Routine

This backdoor connects to the following URL(s) to download its component file(s):

  • http://{BLOCKED}.98.236/xkaoh.exe

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.966.02

FIRST VSAPI PATTERN DATE:

07 Jun 2013

VSAPI OPR PATTERN File:

9.967.00

VSAPI OPR PATTERN Date:

08 Jun 2013

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

Reset Internet security settings

[ Learn More ]

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_LOCAL_MACHINE\System\ControlSet001\Control\MediaResources
    • msvideo
  • In HKEY_LOCAL_MACHINE\System
    • InfoTime

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_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
    • 5D6B8EB5 = "%Windows%\5D6B8EB5\svchsot.exe"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
    • rdchelp = "%Program Files%\Common Files\xkaoh.exe"
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\System
    • DisableCMD = "0"

Step 6

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.
  • %Windows%\5D6B8EB5

Step 7

Search and delete these files

[ 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.
  • %Program Files%\Common Files\xkaoh.exe
  • {malware path}\xkaoh.exe
  • %System%\drivers\etc\host.ics
  • {malware path}\{malware file name}-up.txt

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_MORIX.POR. 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.


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