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Virus Profile: Downloader.gen.a!A7F4A02A4DA0

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Virus Profile information details
Risk Assessment: Home Low | Corporate Low
Date Discovered: 11/13/2012
Date Added: 11/13/2012
Origin: Unknown
Length: 247098
Type: Trojan
Subtype: Generic
DAT Required: 6895
Removal Instructions
   
 
 
   

Description

This is a Trojan detection. Unlike viruses, Trojans do not self-replicate. They are spread manually, often under the premise that they are beneficial or wanted. The most common installation methods involve system or security exploitation, and unsuspecting users manually executing unknown programs. Distribution channels include e-mail, malicious or hacked Web pages, Internet Relay Chat (IRC), peer-to-peer networks, etc.

Indication of Infection

This symptoms of this detection are the files, registry, and network communication referenced in the characteristics section.

Methods of Infection

Trojans do not self-replicate. They are spread manually, often under the premise that the executable is something beneficial. Distribution channels include IRC, peer-to-peer networks, newsgroup postings, e-mail, etc.

   

Virus Characteristics

This is a Trojan

File PropertiesProperty Values
McAfee DetectionDownloader.gen.a
Length247098 bytes
MD5a7f4a02a4da06fba19c77df42b93b057
SHA1fd1f1bae0e8108ac918fbd4a8cee3bed994afcb7


Other Common Detection Aliases

Company NamesDetection Names
ahnlabWin-Trojan/Agent.29090
avastWin32:Agent-UNG
AVG (GriSoft)SHeur.BAQZ
aviraTR/Crypt.ZPACK.Gen
KasperskyPacked.Win32.PolyCrypt.d
BitDefenderGen:Trojan.Heur.GM.0440441920
Dr.WebTrojan.MulDrop.11916
eSafe (Alladin)Infected
F-ProtW32/Downloader!1070
FortiNetW32/PolyCrypt.D!tr
Microsofttrojandownloader:win32/small.cba
SymantecBackdoor.Trojan
EsetWin32/Kryptik.HAF
normanagent.izeo
SophosMal/Generic-L
Trend MicroPAK_Generic.002
vba32Malware-Cryptor.Win32.RPoly
Vet (Computer Associates)Win32/Agent.DU

Other brands and names may be claimed as the property of others.


ActivitiesRisk Levels
Adds or modifies winlogon userinit registry value. Could be used to launch a program on startup.Medium
Process attempts to call itself recursivelyLow
Adds or modifies Internet Explorer cookiesLow
No digital signature is presentInformational


McAfee ScansScan Detections
McAfee BetaDownloader.gen.a
McAfee SupportedDownloader.gen.a



System Changes

Some path values have been replaced with environment variables as the exact location may vary with different configurations.
e.g.
%WINDIR% = \WINDOWS (Windows 9x/ME/XP/Vista/7), \WINNT (Windows NT/2000)
%PROGRAMFILES% = \Program Files


The following files were analyzed:

FD1F1BAE0E8108AC918FBD4A8CEE3BED994AFCB7

The following files have been added to the system:

  • %WINDIR%\SYSTEM32\drivers\svchost.exe
  • %USERPROFILE%\Local Settings\Application Data\windowsupdate.exe

The following registry elements have been changed:

  • HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\RUN\AUTOLOAD = %USERPROFILE%\Local Settings\Application Data\windowsupdate.exe
  • HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\RUN\NTUSER = %WINDIR%\SYSTEM32\drivers\svchost.exe
  • HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\WINLOGON\SHELL = Explorer.exe
  • HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\WINLOGON\UIHOST = logonui.exe
  • HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\WINLOGON\USERINIT = %WINDIR%\SYSTEM32\userinit.exe,
  • HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\RUN\AUTOLOAD = %USERPROFILE%\Local Settings\Application Data\windowsupdate.exe
  • HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\RUN\NTUSER = %WINDIR%\SYSTEM32\drivers\svchost.exe
  • HKEY_LOCAL_MACHINE\SYSTEM\ControlSet\SERVICES\SCHEDULE\IMAGEPATH = %WINDIR%\SYSTEM32\drivers\svchost.exe

   

All Users:

Please use the following instructions for all supported versions of Windows to remove threats and other potential risks:

1.Disable System Restore .

2.Update to current engine and DAT files for detection and removal.

3.Run a complete system scan.

Modifications made to the system Registry and/or INI files for the purposes of hooking system startup, will be successfully removed if cleaning with the recommended engine and DAT combination (or higher).

1. Please go to the Microsoft Recovery Console and restore a clean MBR.

On windows XP:

Insert the Windows XP CD into the CD-ROM drive and restart the computer.
When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
Select the Windows installation that is compromised and provide the administrator password
Issue 'fixmbr' command to restore the Master Boot Record
Follow onscreen instructions
Reset and remove the CD from CD-ROM drive.


On Windows Vista and 7:

Insert the Windows CD into the CD-ROM drive and restart the computer.
Click on "Repair Your Computer"
When the System Recovery Options dialog comes up, choose the Command Prompt.
Issue 'bootrec /fixmbr' command to restore the Master Boot Record
Follow onscreen instructions
Reset and remove the CD from CD-ROM drive.