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TROJ_AGENT.YFH

October 26, 2010
 PLATFORM:

Windows 98, ME, NT, 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type:

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan adds registry entries to enable its automatic execution at every system startup.



  TECHNICAL DETAILS

File Size:

3959296 bytes

Memory Resident:

Yes

Initial Samples Received Date:

17 Dec 2009


Autostart Technique


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


It drops the following files:

    • %System%\wisdstr.exe
    • C:\DOCUMENTS AND SETTINGS\ALL USERS\START MENU\Programs\Startup\win.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)



Other Details


This Trojan adds the following lines or registry entries as part of its routine:


  • HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\Windows\CURRENTVERSION\RunOnce\Cleanup
    C:\cleanup.exe
    HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\Windows\CURRENTVERSION\Run\avg
    C:\Arquivos de programas\avg.exe


      SOLUTION


    Step 1


    Terminate the malware/grayware/spyware process:

    [ Learn More ]
    Notes=
  • For Windows 98 and ME users, 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.
  • 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.
  • If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.


    • Step 2


    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.

    • HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\Windows\CURRENTVERSION\Run\Windows32
      • C:\Arquivos de programas\win.exe=REG_SZ


    Step 3


    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.
    • C:\DOCUMENTS AND SETTINGS\ALL USERS\START MENU\Programs\Startup\win.exe

    Note: To do a search for the following files, right-click Start then click Search... or Find..., depending on the version of Windows you are running.For each file to be deleted, type its file name in the Named input box. In the Look In drop-down list, select My Computer, then press Enter.
  • Once located, select the file then press SHIFT+DELETE to permanently delete the file.
  • Repeat the said steps for all files listed.


    • Step 4


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

    *Note: 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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