A new variant of MyDoom worm - Mydoom.Y, was found on September 14th, 2004. It spreads in emails with different subject and body texts, downloads and activates a backdoor.This variant was already detected generically as I-Worm.MyDoom.gen. This variant seems to launch a DDoS attack against www.symantec.com.
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The worm is a PE executable file 88640 bytes long packed with FSG file compressor. The unpacked file's size is over 118 KiB.
When run, the worm creates a mutex 'Sept-Symantec-Attack', copies itself as "oz11111.exe" to Windows System Directory and as "oz2.exe" in the main Windows folder.
It drops several other components, registry keys are created for all the executables as follows:
(First tries HKLM and falls back into HKCU if the registry key can't be openened)
where "%WinSysDir%" represents Windows System directory, "%WinDir%" the main Windows folder and "%WinTempDir%" the Windows Temporary files folder.
The worm will also drop a text file named 'About_Mydoom.txt' in the Windows System folder, with contents refering to the actions performed by the worm, the text in the file follows:
------------------- About_Mydoom.txt contents ------------------ Contain 1- ATTACK www.symantec.com On Sept 29 2004 starting at 2 2- drops yahoo keylogger that open 4321, http://victim_ip:4321/ 3- drops 2 pictures that will not be showing to the victim 4- drops a downxz.bat which download Bacdoor.Nemog.c 5- drops services.exe , zincite.a 6- Retrieves email addresses from the Outlook address book and files on fixed disks, ram disks, and in the following registry key and folders: %Userprofile%\Local Settings\Temporary Internet Files %Userprofile%\Desktop %Userprofile%\My Documents %Userprofile%\Application Data , etc queries HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4\Wab File Name and searches for emails. go and detect the other information. In a difficult world In a nameless time I want to survive So, you will be mine!!,second author Nemog and ZinCite :P¿mnopqrst ------------------- About_Mydoom.txt contents ------------------
The worm spreads by sending its infected attachment to all email addresses found on an infected computer. The worm looks for email addresses in Windows Address Book and in the files with the following extensions:
The worm avoids sending emails to email addresses that contain any of the following substrings:
The subject of infected emails is selected from the following variants:
The body text of infected emails is selected from the following variants:
The worm can send itself as an executable attachment or in a ZIP archive with one of the following names:
with any of the following extensions appended: