Analysis by: Sabrina Lei Sioting
 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Propagates via removable drives

This worm drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size: 817,258 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 07 Sep 2010
Payload: Connects to URLs/Ips

Installation

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

  • %system%\csrcs.exe

It drops the following files:

  • %system%\\autorun.inf - detected as Mal_Otorun1.
  • {drive letter}\\khq

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
csrcs = %system%\csrcs.exe

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = Explorer.exe csrcs.exe

(Note: The default value data of the said registry entry is Explorer.exe.)

Other System Modifications

This worm modifies the following registry entries to hide files with Hidden attributes:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 2

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
SuperHidden = 0

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = 0

(Note: The default value data of the said registry entry is 1.)

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • bcafpr.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

;garbage
[AutoRun]
;garbage
open=bcafpr.exe
;garbage
shell\open\Command=bcafpr.exe
;garbage
shell\open\Default=1
;garbage
shell\explore\Command=bcafpr.exe
;garbage

Other Details

This worm connects to the following possibly malicious URL:

  • http://www.{BLOCKED}myip.com/automation/n09230945.asp
  • http://{BLOCKED}u.akakapatama.com:2547/Now/fall2.gif

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 07.444.01
VSAPI PATTERN Date: 07 Sep 2010
VSAPI PATTERN Date: 9/7/2010 12:00:00 AM

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

Restart in Safe Mode

[ Learn More ]

Step 3

Remove malware files dropped/downloaded by WORM_HARAKIT.AMF

    Mal_Otorun1

Step 4

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.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
csrcs = %system%\csrcs.exeRESTORE
  • Close Registry Editor.

    • Step 5

    Restore this modified 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.

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    Shell  = Explorer.exe csrcs.exe
    default value is Shell = Explorer.exe

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    Hidden = 2
    default value is 1

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    SuperHidden = 0
    dafault value is 1

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    ShowSuperHidden = 0
    deafult value is 1
    RESTORE
  • Close Registry Editor.

    • Step 6

    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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DRM\amty RESTORE
  • Close Registry Editor.

    • Step 7

    Search and delete this file

    [ Learn More ]
    There may be some component 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.  {drive letter}\khq
    %system%\autorun.infDATA_GENERIC
  • In the Look In drop-down list, select My Computer, then press Enter.
  • Once located, select the file then press SHIFT+DELETE to permanently delete the file.

    • Step 8

    Search and delete AUTORUN.INF files created by WORM_HARAKIT.AMF that contain these strings

    [ Learn More ]
    DATA_GENERIC
  • If the lines are present, delete the file.
  • Repeat steps 3 to 6 for the remaining AUTORUN.INF files in other remaining removable drives.
  • Close Search Results.

    • Step 9

    Scan your computer with your Trend Micro product to delete files detected as WORM_HARAKIT.AMF. 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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