TROJ_AGENT.WCQ

October 09, 2012
 Analysis by: Cris Nowell Pantanilla
 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size:

67,584 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

20 May 2011

Payload:

Connects to URLs/IPs

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_DROPPR.CQ

Installation

This Trojan adds the following processes:

  • IEXPLORE.EXE

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{F608F326-3CC4-AF48-BDD5-2614AD7E2923}
StubPath = %System%:mstrc.scr

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\hol.txt
  • %Program Files%\Outlook Express\msvc7.dll
  • %Windows%\system\VER.SYS

(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.. %Program Files% is the default Program Files folder, usually C:\Program Files.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}.215.58

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

8.166.15

FIRST VSAPI PATTERN DATE:

10 May 2011

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

Remove malware files dropped/downloaded by TROJ_AGENT.WCQ

    TROJ_DROPPR.CQ

Step 3

Restart in Safe Mode

[ Learn More ]

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {F608F326-3CC4-AF48-BDD5-2614AD7E2923}

Step 5

Search and delete this file

[ 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. %User Temp%\hol.txt
%Program Files%\Outlook Express\msvc7.dll
%Windows%\system\VER.SYS

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_AGENT.WCQ. 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.


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