Analysis by: Christopher Daniel So
 Modified by: Sabrina Lei Sioting
ALIASES:

Worm:Win32/Emerleox.gen!A (Microsoft), W32/Fujacks.gen.a (McAfee)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Via physical/removable drives, Dropped by other malware

This file infector arrives via removable drives. It may be dropped by other malware.

It prepends its codes to target files.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system. It uses a list of passwords to gain access to password-protected shares.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 76,807 bytes
Memory Resident: Yes
Initial Samples Received Date: 17 Apr 2012
Payload: Compromises network security, Connects to URLs/IPs, Terminates processes

Arrival Details

This file infector arrives via removable drives.

It may arrive via network shares.

It may be dropped by the following malware:

  • PE_FUJACKS.RC

Installation

This file infector drops the following copies of itself into the affected system:

  • %System%\drivers\TXPlatform.exe

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

It drops the following files:

  • %System Root%\go.sys
  • %Program Files%\WinRAR\myrar.txt

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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).)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Explorer = "%System%\drivers\TXPlatform.exe"

Other System Modifications

This file infector adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
{application name}
Debugger = "ntsd -d"

It modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_CLASSES_ROOT\HTTP\shell\
open\command
{default} = ""%Program Files%\InternetExplorer\iexplore.exe" -nohome"

(Note: The default value data of the said registry entry is "%Program Files%\Internet Explorer\iexplore.exe" -nohome.)

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
HTTP\shell\open\
command
{default} = ""%Program Files%\InternetExplorer\iexplore.exe" -nohome"

(Note: The default value data of the said registry entry is "%Program Files%\Internet Explorer\iexplore.exe" -nohome.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoDriveTypeAutoRun = "80"

(Note: The default value data of the said registry entry is 91.)

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

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

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

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wscsvc

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_WSCSVC

Where {application name} may be any of the following:

  • 360Safe.exe
  • 360tray.exe
  • AVP.exe
  • CCenter.exe
  • RavMon.exe
  • RavMonD.exe
  • RavStub.exe
  • RavTask.exe

File Infection

This file infector infects the following file types:

  • .exe

It prepends its codes to target files.

Propagation

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

  • ¡¡¡¡¡¡.exe

It uses the following file names for the copies it drops into shared networks:

  • Cool_GameSetup.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=¡¡¡¡¡¡.exe
shell\open=´ò¿ª(&O)
shell\open\Command=¡¡¡¡¡¡.exe
shell\open\Default=1
shell\explore=×ÊÔ´¹ÜÀíÆ÷(&X)
shell\explore\Command=¡¡¡¡¡¡.exe

It uses the following list of passwords to gain access to password-protected shares:

  • password
  • harley
  • 123456
  • pussy
  • mustang
  • shadow
  • qwerty
  • baseball
  • letmein
  • 12345678
  • 12345
  • admin
  • 5201314
  • qq520
  • 1234567
  • 123456789
  • 654321
  • 54321
  • 000000
  • 11111111
  • 88888888
  • passwd
  • database
  • abc123
  • sybase
  • 123qwe
  • server
  • computer
  • super
  • 123asd
  • ihavenopass
  • godblessyou
  • enable
  • alpha
  • 111111
  • 121212
  • 123123
  • 1234qwer
  • 123abc
  • patrick
  • administrator
  • fuckyou
  • test123
  • temp123
  • owner
  • login
  • Login
  • pw123
  • mypc123
  • admin123
  • mypass
  • mypass123
  • 901100
  • Administrator
  • Guest
  • admin

Process Termination

This file infector terminates the following services if found on the affected system:

  • Schedule
  • sharedaccess
  • kavsvc
  • kavsvc
  • McAfeeFramework
  • McShield
  • McTaskManager
  • McAfeeFramework
  • McShield
  • McTaskManager
  • navapsvc
  • wscsvc
  • KPfwSvc
  • SNDSrvc
  • ccProxy
  • ccEvtMgr
  • ccSetMgr
  • SPBBCSvc
  • Symantec Core LC
  • NPFMntor
  • MskService
  • FireSvc
  • RsCCenter
  • RsRavMon
  • RsCCenter
  • RsRavMon
  • kav
  • KAVPersonal50
  • AVP
  • McAfeeUpdaterUI
  • Network Associates Error Reporting Service
  • ShStatEXE

It terminates the following processes if found running in the affected system's memory:

  • Mcshield.exe
  • VsTskMgr.exe
  • naPrdMgr.exe
  • UpdaterUI.exe
  • TBMon.exe
  • scan32.exe

Other Details

This file infector closes application windows that contain the following strings in the title bar:

  • VirusScan
  • NOD32
  • Symantec AntiVirus
  • System Safety Monitor
  • System Repair Engineer
  • IceSword

It attempts to access the following websites to download files, which are possibly malicious:

  • http://{BLOCKED}g08.com/down/down.txt

However, as of this writing, the said sites are inaccessible.

NOTES:

Infection Routine

It searches for files with the following file extensions:

  • asp
  • htm
  • html

It then appends an iframe to these files that redirects users to http://{BLOCKED}g08.com/down/htmmm/mm.Htm . Infected files are detected as HTML_IFRAME.QT. It also creates a file named Desktop_.ini in every folder it has searched through to serve as its infection marker. This file contains the date of infection.

It avoids infecting files in the following folders:

  • WINDOWS
  • WinRAR
  • WINNT
  • system32
  • Documents and Settings
  • System Volume Information
  • Recycled
  • Windows NT
  • WindowsUpdate
  • Windows Media Player
  • Outlook Express
  • Internet Explorer
  • NetMeeting
  • Common Files
  • ComPlus Applications
  • Messenger
  • InstallShield Installation Information
  • Microsoft Frontpage
  • Movie Maker
  • MSN Gamin Zone

Propagation Routine

The dropped autorun.inf is detected as Mal_Otorun1.

Other Details

It also deletes the following hidden network share:

  • admin$

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.918.02
FIRST VSAPI PATTERN DATE: 17 Apr 2012
VSAPI OPR PATTERN File: 8.918.02
VSAPI OPR PATTERN Date: 18 Apr 2012

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 the malware/grayware file that dropped/downloaded PE_FUJACKS.RC-O

Step 3

Remove the malware/grayware file dropped/downloaded by PE_FUJACKS.RC-O

Step 4

Identify and terminate files detected as PE_FUJACKS.RC-O

[ Learn More ]
  1. 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 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Explorer = "%System%\drivers\TXPlatform.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\{application name}
    • Debugger = "ntsd -d"

Step 6

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_CLASSES_ROOT\HTTP\shell\open\command
    • From: {default} = ""%Program Files%\InternetExplorer\iexplore.exe" -nohome"
      To: {default} = "%Program Files%\Internet Explorer\iexplore.exe" -nohome
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\HTTP\shell\open\command
    • From: {default} = ""%Program Files%\InternetExplorer\iexplore.exe" -nohome"
      To: {default} = "%Program Files%\Internet Explorer\iexplore.exe" -nohome
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • From: NoDriveTypeAutoRun = "80"
      To: NoDriveTypeAutoRun = 91
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
    • From: CheckedValue = "0"
      To: CheckedValue = 1

Step 7

Search and delete this file

[ 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.
{folder path}\Desk_top_.ini
%System Root%\go.sys
%Program Files%\WinRAR\myrar.txt

Step 8

Search and delete AUTORUN.INF files created by PE_FUJACKS.RC-O that contain these strings

[ Learn More ]
[AutoRun]
OPEN=¡¡¡¡¡¡.exe
shell\open=´ò¿ª(&O)
shell\open\Command=¡¡¡¡¡¡.exe
shell\open\Default=1
shell\explore=×ÊÔ´¹ÜÀíÆ÷(&X)
shell\explore\Command=¡¡¡¡¡¡.exe

Step 9

Scan your computer with your Trend Micro product to delete files detected as PE_FUJACKS.RC-O. 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 10

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root
    • LEGACY_WSCSVC
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • wscsvc


Did this description help? Tell us how we did.

Related Malware