Analysis by: Christopher Daniel So
ALIASES:

HackTool:Win32/Wpakill (Microsoft), Win32/HackTool.WpaKill.C (Nod32), W32/Wpakill.A.gen!Eldorado (Authentium), W32/Wpakill.A.gen!Eldorado (FProt), Hack-Tool:W32/WPAKill.C (FSecure), not-a-virus.Hacktool.Wpakill (Ikarus)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Hacking Tool

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  TECHNICAL DETAILS

File Size: Varies
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 18 Dec 2010

Installation

This hacking tool drops the following copies of itself into the affected system:

  • %System%\{malware file name}.dll

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Other System Modifications

This hacking tool modifies the following file(s):

  • %Windows%\inf\syssetup.PNF

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\
WINDOWS NT\CURRENTVERSION\Winlogon\
Notify\Antiwat
Asynchronous = 0

HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\
WINDOWS NT\CURRENTVERSION\Winlogon\
Notify\Antiwat
Impersonate = 0

HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\
WINDOWS NT\CURRENTVERSION\Winlogon\
Notify\Antiwat
DllName = "{malware file name}.dll"

HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\
WINDOWS NT\CURRENTVERSION\Winlogon\
Notify\Antiwat
Logon = "onLogon"

HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\
WINDOWS NT\CURRENTVERSION\WPAEvents
OOBETimer = {random}

It modifies the following registry entries:

HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\
Windows\CURRENTVERSION\GrpConv
Log = "{random string}"

(Note: The default value data of the said registry entry is "Uninit Application.".)

  SOLUTION

Minimum Scan Engine: 8.900

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

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 NT\CURRENTVERSION\Winlogon\Notify\Antiwat
    • Asynchronous=0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\Winlogon\Notify\Antiwat
    • Impersonate=0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\Winlogon\Notify\Antiwat
    • DllName={malware file name}.dll
  • In HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\Winlogon\Notify\Antiwat
    • Logon=onLogon
  • In HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\WPAEvents
    • OOBETimer={random}

Step 4

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\GrpConv
    • From: Log={random string}
      To: Log=Uninit Application.

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as HKTL_WPAKILL. 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 6

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Windows%\inf\syssetup.PNF


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