Trojan:W32/Delf.AOO is a trojan. This malware uses a hidden browser process (e.g. iexplorer.exe) to hide itself from the systems' process list. It terminates antivirus applications by searching for antivirus company strings in all application window title headers.


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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.

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Technical Details

Upon execution, the malware detected asTrojan.Win32.Delf.aoo will create the following files:

  • %windir%\system32\zsmscc071031.exe
  • %windir%\zsmscc16.ini
  • %windir%\system32\zsmscc071031.dll
  • %windir%\system32\zsmscc32.dll

Note: zsmscc071031.exe is a copy of the original file.After the trojan's file is started by the user, it installs itself to the system by copying its file to the Windows folder.It also creates a startup key value in the Registry for the copied file. This is done to ensure that the trojan's file is started every time Windows boots. The startup key value is created under the following Registry key:

  • HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\runzsmscc = rundll32.exe C:\WINDOWS\system32\zsmscc071006.dll mymain

Furthermore, Trojan.Win32.Delf.aoo launches an instance of Microsoft Internet Explorer as a hidden process with its code is injected into the process.After hiding itself on the system, it will download these files depending on the variant:

  • https://j[removed]
  • https://a[removed]
  • https://a[removed]


This trojan terminates applications that have the following text strings in their application window title headers:

  • 360safe
  • duba
  • kaspersky
  • mcafee
  • nod32
  • rising
  • Symantec AntiVirus

Date Created: -

Date Last Modified: -