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Worm:W32/Revois

Classification

Category:Malware
Type:Worm
Platform:W32
Aliases:

Trojan-Downloader.Win32.VB.eex, Win32.Worm.VB.NVA, Worm:Win32/VB.AT (Microsoft), Win32.Worm.VB.NVA (Other)

Summary

Upon execution of Worm:W32/Revois, the files detailed below are created.

The worm also makes a variety of Windows Registry amendments, some of which prevent certain security programs from running.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

File System Changes

Creates these files:

  • Autorun.inf
  • C:\ntldr~6
  • C:\ntldr~8
  • C:\RECYCLEP\Pagefile.exe (hidden)
  • %windir%\regedt32.sys
  • %windir%\Sysinf.bat
  • %windir%\Help\HelpCat.exe
  • %windir%\system\KavUpda.exe
  • %windir%\system32\Option.bat
  • %Documents and Settings\Default User\Templates\excel.exe
  • %Documents and Settings\Default User\Templates\excel4.exe
  • %Documents and Settings\Default User\Templates\winword.exe
  • %windir%\system32\ExceRes
  • %windir%\system32\WordRes

Registry Modifications

Creates these keys:

  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL] "CheckedValue"=dword:00000000
  • [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer] "NoDriveTypeAutoRun"=dword:b5
  • [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced] "HideFileExt"=dword:00000001
  • [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer] "DisallowRun"=dword:00000001
  • [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\DisallowRun] "1"="avp.exe" "2"="RfwMain.exe" "3"="Rfwsrv.exe" "4"="RavMoD.exe" "5"="CCenter.exe" "6"="RavMon.exe" "7"="RavStub.exe" "8"="RavService.exe" "9"="Rav.exe" "10"="rfwcfg.exe" "11"="KPFW32.EXE" "12"="KPFW32X.EXE" "13"="KAVPFW.EXE" "14"="KAV32.EXE" "15"="KAVStart.EXE"
  • [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced] "Hidden"=dword:00000002 "SuperHidden"=dword:00000001
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\regedit.exe] "Debugger"="D:\\RECYCLER\\????8.exe"
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\RfwMain.exe] "Debugger"="D:\\RECYCLER\\????8.exe"
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\Rfwsrv.exe] "Debugger"="D:\\RECYCLER\\????8.exe"
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\RavMoD.exe] "Debugger"="D:\\RECYCLER\\????8.exe"
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\avp.exe] "Debugger"="D:\\RECYCLER\\????8.exe"
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\Rav.exe] "Debugger"="D:\\RECYCLER\\????8.exe"
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\360Safe.exe] "Debugger"="D:\\RECYCLER\\????8.exe"
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\360tray.exe] "Debugger"="D:\\RECYCLER\\????8.exe"
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\KAVStart.EXE] "Debugger"="D:\\RECYCLER\\????8.exe"
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\taskmgr.exe] "Debugger"="D:\\RECYCLER\\????8.exe"

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