Analysis by: Nikko Tamana

ALIASES:

W32/QQPass.GLE!tr.pws (Fortinet), Trojan-Dropper.Win32.Flystud (Ikarus), Trojan-PSW.Win32.QQPass.spa (Kaspersky), PWS:Win32/QQpass.CI (Microsoft)

 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:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Via physical/removable drives, Propagates via removable drives

This worm arrives via removable drives. 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 steals certain information from the system and/or the user.

It sends gathered information to a predetermined email address using its own Simple Mail Transfer Protocol (SMTP) engine.

  TECHNICAL DETAILS

File Size: 1,148,978 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 22 Feb 2013
Payload: Steals information

Arrival Details

This worm arrives via removable drives.

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 copies of itself into the affected system and executes them:

  • %Program Files%\Windows Media Player\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\autorun.inf\svchost.exe¡¡

(Note: %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).)

It drops the following file(s)/component(s):

  • {Malware Path}\CQ.bat - Non-malicious; Kills qq.exe (IM QQ) then deletes itself
  • {Malware Path}\temp.bat - Non-malicious; Modifies the Access Control List by denying everyone access to change (write) Windows Media Player then deletes itself
  • %User Temp%\E_N4\internet.fne - Non-malicious
  • %User Temp%\E_N4\krnln.fnr - Non-malicious
  • %User Temp%\E_N4\Md5.fne - Also detected as WORM_QQPASS.BFN
  • %User Temp%\E_N4\eAPI.fne - Non-malicious

(Note: %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 creates the following folders:

  • %User Temp%\E_N4
  • %System Root%\autorun.inf
  • %System Root%\autorun.inf\ÎļþÃâÒß.
  • %Program Files%\autorun.inf
  • %Program Files%\autorun.inf\ÎļþÃâÒß.
  • %Program Files%\Windows Media Player\autorun.inf
  • %Program Files%\Windows Media Player\autorun.inf\ÎļþÃâÒß.

(Note: %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.. %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 worm modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "Userinit,"%Program Files%\Windows Media Player\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\autorun.inf\svchost.exe¡¡"

(Note: The default value data of the said registry entry is "%System%\userinit.exe,".)

Other System Modifications

This worm adds the following registry keys:

HKEY_CLASSES_ROOT\.exe¡¡

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.exe¡¡

HKEY_CURRENT_USER\Software\LoveQ

It adds the following registry entries as part of its installation routine:

HKEY_CLASSES_ROOT\.exe¡¡
{Default} = "exefile"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.exe¡¡
{Default} = "exefile"

HKEY_CURRENT_USER\Software\LoveQ
first = "closeQQ"

Information Theft

This worm steals the following information:

  • User log-in credentials for IM QQ

Stolen Information

This worm sends gathered information to a predetermined email address using its own Simple Mail Transfer Protocol (SMTP) engine.

NOTES:

It drops copies of itself using the folder names in the root directory of all physical and removable drives then sets the attributes of the original folders to Hidden. The dropped copies' icon looks like a folder. By doing so, it tricks users into clicking the dropped copies. When a dropped copy is executed, the original folder opens to make the user think that it has opened the original folder.

Its added folders are hidden. The autorun.inf folders it adds are a shortcut to Recycle Bin.

It monitors the following websites of QQ, a popular Chinese instant messaging application, to steal user-entered login details:

  • http://{BLOCKED}m.qq.com/?ptlang=2052&ADUIN=0&ADSESSION=0&ADTAG=CLIENT.QQ.2173_NewAccount_Btn
  • https://{BLOCKED}t.qq.com/cgi-bin/auth_forget?ptlang=2052&ADUIN=0&ADSESSION=0&ADTAG=CLIENT.QQ.2173_ForgetPsw

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.746.03
FIRST VSAPI PATTERN DATE: 22 Feb 2013
VSAPI OPR PATTERN File: 9.747.00
VSAPI OPR PATTERN Date: 23 Feb 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

Scan your computer with your Trend Micro product and note files detected as WORM_QQPASS.BFN

Step 3

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: Userinit = "Userinit,"%Program Files%\Windows Media Player\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\{random character}\autorun.inf\svchost.exe¡¡"
      To: Userinit = "%System%\userinit.exe,"

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

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.
  • %User Temp%\E_N4

Step 6

Search and delete these files

[ 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.
  • {Malware Path}\CQ.bat
  • {Malware Path}\temp.bat

Step 7

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
    • .exe¡¡
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes
    • .exe¡¡
  • In HKEY_CURRENT_USER\Software
    • LoveQ

Step 8

  1. Open a command prompt.
    • For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run. In the Search box, type CMD then press Enter.
    • For Windows Vista and Windows 7 users, click Start, type CMD in the Search input field then press Enter.
  2. In the CMD console, type the following:

    ATTRIB [+R | -R] [+A | -A ] [+S | -S] [+H | -H] [+I | -I] [drive:][path][file name] [/S [/D] [/L]]

    Where:
    + Sets an attribute.
    - Clears an attribute
    R Read-only file attribute
    A Archive file attribute
    S System file attribute
    H Hidden file attribute
    I Not content indexed file attribute
    [drive:][path][filename]
    Specifies a file or files for attrib to process
    /S Processes matching files in the current folder and all subfolders.
    /D Processes folders
    /L Work on the attributes of the Symbolic Link versus the target of the Symbolic Link
    Example:
    To unhide all files and folders (including subfolders) in drive D:
    ATTRIB –H D:\* /S /D
  3. Repeat Step 3 for folders and files in other drives or directories.

Step 9

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

NOTES:
Before restarting to normal mode, you must do the step below to delete the added autorun.inf and {random character} folders.

Execute the following commands from the CMD prompt:

rmdir "%System Root%\autorun.inf" /s /q r
mdir "%Program Files%\autorun.inf" /s /q
rmdir "%Program Files%\Windows Media Player\autorun.inf" /s /q
rmdir "{Removable Drive}:\autorun.inf" /s /q
cacls "%Program Files%\Windows Media Player\{First character of added folder}" /r everyone /e
rmdir "%Program Files%\Windows Media Player\{First character of added folder}" /s /q


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