Analysis by: Karl Dominguez

 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Propagates via removable drives

This worm arrives by connecting affected removable drives to a system. It may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.

It uses the default Windows folder icon to trick users into opening the file. Double-clicking on the file executes this malware.

It 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: 1,393,062 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 01 May 2009
Payload: Connects to URLs/Ips

Arrival Details

This worm arrives by connecting affected removable drives to a system.

It may be downloaded by other malware/grayware/spyware from remote sites.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

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

  • %System%\{random folder name}\{random characters}.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It drops the following component file(s):

  • %System%\{random folder name}\krnln.fnr - detected as WORM_AUTORUN.EIK
  • %System%\{random folder name}\eAPI.fne - detected as WORM_AUTORUN.EIK
  • %System%\{random folder name}\dp1.fne - detected as WORM_AUTORUN.EIK
  • %System%\{random folder name}\shell.fne - detected as WORM_AUTORUN.EIK
  • %System%\{random folder name}\cnvpe.fne - detected as WORM_AUTORUN.EIK
  • %System%\{random folder name}\com.run - detected as WORM_AUTORUN.EIK
  • %System%\{random folder name}\internet.fne - detected as WORM_AUTORUN.EIK
  • %System%\{random folder name}\RegEx.fnr - detected as WORM_AUTORUN.EIK
  • %System%\{random folder name}\spec.fne - detected as WORM_AUTORUN.EIK
  • %System%\{random folder name}\{random characters}.inf - non-malicious
  • %System%\{random folder name}\{random characters}.txt - non-malicious
  • %User Temp%\E_N4\krnln.fnr - detected as WORM_AUTORUN.EIK
  • %User Temp%\E_N4\eAPI.fne - detected as WORM_AUTORUN.EIK
  • %User Temp%\E_N4\dp1.fne - detected as WORM_AUTORUN.EIK
  • %User Temp%\E_N4\shell.fne - detected as WORM_AUTORUN.EIK
  • %User Temp%\E_N4\cnvpe.fne - detected as WORM_AUTORUN.EIK

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %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.)

It creates the following folders:

  • %System%\{random folder name}
  • %User Temp%\E_N4

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %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.)

It uses the default Windows folder icon to trick users into opening the file. Double-clicking on the file executes this malware.

Autostart Technique

This worm drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:

  • {malware file name}.lnk

Propagation

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

  • Recycled.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:

[AutoRun]
open=Recycled.exe
shell\1={random characters}
shell\1\Command=Recycled.exe
shell\2\={random characters}
shell\2\Command=Recycled.exe
shellexecute=Recycled.exe

Adware Routine

This worm connects to the following URLs to download and display ads:

  • http://{BLOCKED}in.com/ul.htm

Other Details

This worm does the following:

  • It dropies of itself in removable drives.
  • It uses the names of the folders located on the said drives for their file names.
  • It sets the attributes of the original folders to Hidden.
  • It does not have information theft capabilities.

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 6.104.06
FIRST VSAPI PATTERN DATE: 01 May 2009

Step 1

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

Step 2

Identify and terminate files detected as WORM_AUTORUN.EIK

[ Learn More ]
  1. For Windows 98 and ME users, Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

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.  {malware file name}.lnk

Step 4

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.
%System%\{malware path}
%User Temp%\E_N4

Step 5

Search and delete AUTORUN.INF files created by WORM_AUTORUN.EIK that contain these strings

[ Learn More ]
[AutoRun]
open=Recycled.exe
shell\1={random characters}
shell\1\Command=Recycled.exe
shell\2\={random characters}
shell\2\Command=Recycled.exe
shellexecute=Recycled.exe

Step 6

Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.EIK 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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