Analysis by: Nice Yutuc
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size: 343,040 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 19 Jan 2012

Arrival Details

This Trojan 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 Trojan drops the following component file(s):

  • %Application Data%a\446947ea
  • %Application Data%a\e26db7b0
  • %Application Data%\c4b0fca6
  • %User Profile%\Templates\e179235a

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

It drops the following copies of itself into the affected system:

  • %Application Data%\qkm.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

Autostart Technique

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

HKEY_CLASSES_ROOT\mdaw\shell\
open\command
(Default) = ""%Application Data%\qkm.exe" -a "%1" %*"

Other System Modifications

This Trojan modifies the following registry entries:

HKEY_CLASSES_ROOT\.exe
(Default) = "mdaw"

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

It also creates the following registry entry(ies) as part of its installation routine:

HKEY_CURRENT_USER\Software\Classes\
.exe
(Default) = "mdaw"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows
Version = "bb3b2d98"

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wuauserv

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.726.03
FIRST VSAPI PATTERN DATE: 22 Jan 2012
VSAPI OPR PATTERN File: 8.727.00
VSAPI OPR PATTERN Date: 23 Jan 2012

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

Terminate a process file/s detected as TROJ_FAKEAV.ECIN

[ Learn More ]

*Note: If the detected file/s is/are not displayed in theWindows Task Manager, continue doing the next steps.

Step 3

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_CLASSES_ROOT\.exe
    • From: (Default) = "mdaw"
      To: (Default) = "exefile"

Step 4

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_CLASSES_ROOT
    • mdaw

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\Classes\.exe
    • (Default) = "mdaw"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
    • Version = "bb3b2d98"

Step 6

Search and delete these files

[ 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.
  • %Application Data%a\446947ea
  • %Application Data%a\e26db7b0
  • %Application Data%\c4b0fca6
  • %User Profile%\Templates\e179235a

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEAV.ECIN. 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 8

Restore this deleted registry key/value 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\Services
    • wuauserv


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