arrow_back
search
close

WORM_ONLINEG.FC

May 08, 2013
 Analysis by: Anthony Joe Melgarejo
 ALIASES:

Worm:Win32/Taterf.B(Microsoft), Win32/PSW.OnLineGames.NNU trojan(Eset)

 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: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware, Propagates via removable drives

This worm arrives by connecting affected removable drives to a system. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

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

As of this writing, the said sites are inaccessible.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

128,192 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

26 Apr 2013

Payload:

Connects to URLs/IPs, Downloads files

Arrival Details

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

It 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 worm drops the following component file(s):

  • %System%\kavo{random number}.dll - detected as TSPY_ONLINEG.FC
  • %User Temp%\twye.dll - also detected as WORM_ONLINEG.FC

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %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 drops the following copies of itself into the affected system:

  • %System%\kavo.exe

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

Its DLL component is injected to the following process(es):

  • explorer.exe

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
kava = "%System%\kavo.exe"

Other System Modifications

This worm adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\MADOWN

It modifies the following registry entries:

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
ShowSuperHidden = "0"

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

HKEY_LOCAL_MACHINE\Windows\CurrentVersion\
Explorer\Advanced\Folder\
Hidden\SHOWALL
CheckedValue = "0"

(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\Policies\
Explorer
NoDriveTypeAutoRun = "91"

(Note: The default value data of the said registry entry is 95.)

Propagation

This worm drops the following copy of itself in all physical and removable drives:

  • {Drive Letter}:\ipy.cmd

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:

;{random characters}
[AutoRun]
;{random characters}
open=ipy.cmd
;{random characters}
shell\open\Command=ipy.cmd
;{random characters}
shell\open\Default=1
;{random characters}
shell\explore\Command=ipy.cmd
;{random characters}

Download Routine

This worm connects to the following website(s) to download and execute a malicious file:

  • www.{BLOCKED}t.com/hp/zz.rar

As of this writing, the said sites are inaccessible.

Other Details

This worm deletes itself after execution.

  SOLUTION

Minimum Scan Engine:

9.300

VSAPI OPR PATTERN File:

9.881.00

VSAPI OPR PATTERN Date:

07 May 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

Remove malware/grayware files dropped/downloaded by WORM_ONLINEG.FC

Step 3

Restart in Safe Mode

[ Learn More ]

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.

 
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • kava = "%System%\kavo.exe"

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.

  • In HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\Windows\CURRENTVERSION\Policies\Explorer
    • From: NoDriveTypeAutoRun = "91"
      To: NoDriveTypeAutoRun = 95
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: Hidden = "2"
      To: Hidden = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: ShowSuperHidden = "0"
      To: ShowSuperHidden = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: SuperHidden = "0"
      To: SuperHidden = 1
  • In HKEY_LOCAL_MACHINE\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
    • From: CheckedValue = "0"
      To: CheckedValue = 1

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.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
    • MADOWN

Step 7

Search and delete AUTORUN.INF files created by WORM_ONLINEG.FC that contain these strings

[ Learn More ]
;{random characters}
[AutoRun]
;{random characters}
open=ipy.cmd
;{random characters}
shell\open\Command=ipy.cmd
;{random characters}
shell\open\Default=1
;{random characters}
shell\explore\Command=ipy.cmd
;{random characters}

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_ONLINEG.FC. 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 9

Scan your computer with your Trend Micro product to delete files detected as WORM_ONLINEG.FC. 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.


Did this description help? Tell us how we did.