Threat Description

Trojan-Dropper:​W97M/Kukudro.A

Details

Aliases:Trojan-Dropper:​W97M/Kukudro.A, W97M.Kukudro.B, W97M.Kukudro.D
Category:Malware
Type:Trojan-Dropper
Platform:W97M

Summary



A trojan that contains one or more malicious programs, which it will secretly install and execute.



Removal


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.

More

You may wish to refer to the Support Community for further assistance. You also may also refer to General Removal Instructions for a general guide on alternative disinfection actions.



Technical Details



Kukudro is an macro trojan-dropper embedded in a Microsoft Word document. This malware was first spammed to various e-mails addresses, as zip archive file named my_Notebook.doc. Once a user opens the document, it drops and runs a binary executable. Later distributions runs may use varying names for the infected document.The trojan-dropper is written in Visual Basic for Applications (VBA).

Execution

When the infected Word document is opened, the macro code inside of it will be executed. It will decode a binary file from its code and drop it as 666inse_1.exe to the root of the C: drive. Then the macro will execute the dropped 666inse_1.exe file and end. The binary executable is a trojan-downloader called Small.DCU.

Note

In Office 2003 or later, the macro will only execute if macros have been enabled from Word's security settings.Otherwise, the trojan uses a vulnerability in MS Word 97, 2000 and XP; in this case, the macro will be able to execute even though macros are supposed to be disabled. More information on this vulnerability is available at: http://www.microsoft.com/technet/security/Bulletin/MS01-034.mspx.






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