Worm:AutoIt/Autorun.U is a worm - a self-propagating program that can spread itself from one computer to another. Worms may spread themselves via a variety of different channels in order to compromise new computers. Variants of Worm:Win32/Autorun usually spread using methods that include, but may not be limited to, copying themselves to removable or network drives, and placing an autorun.inf file in the root directory of each affected drive in an attempt to ensure that the worm is run when the removable drive is attached, or the network drive is visited from a remote system supporting the Autorun feature.
Installation
When executed, Worm:AutoIt/Autorun.U copies itself to the following locations:
- <system folder>\fdisk.com
- c:\documents and settings\administrator\local settings\temp\svchost.com
- c:\documents and settings\administrator\local settings\temp\scr\logon.exe
- c:\documents and settings\administrator\start menu\programs\startup\sndvol32.exe
- c:\documents and settings\administrator\templates\cache\vmx.exe
- c:\documents and settings\all users\start menu\programs\startup\sndvol32.exe
Note: <system folder> refers to a variable location that is determined by the malware by querying the Operating System. The default installation location for the System folder for Windows 2000 and NT is C:\Winnt\System32; and for XP, Vista, and 7 is C:\Windows\System32.
The malware modifies the following registry entries to ensure that its copy executes at each Windows start:
Adds value: "HotKey"
With data: "c:\documents and settings\administrator\templates\cache\vmx.exe"
To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Adds value: "HotKey"
With data: "c:\documents and settings\administrator\templates\cache\vmx.exe"
To subkey: HKCU\Software\Microsoft\windows\currentversion\run
Adds value: "Shell"
With data: "explorer.exe c:\windows\system32\fdisk.com"
To subkey: HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
The malware creates the following files on an affected computer:
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c:\autorun.inf
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c:\thumbs.db
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c:\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\desktop.ini
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c:\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\temp.db
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c:\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\tmp.db
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c:\documents and settings\administrator\local settings\temp\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\desktop.ini
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c:\documents and settings\administrator\local settings\temp\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\temp.db
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c:\documents and settings\administrator\local settings\temp\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\tmp.db
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c:\documents and settings\administrator\local settings\temp\scr\data.scr
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c:\documents and settings\administrator\templates\cache\desktop.ini
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c:\documents and settings\administrator\templates\cache\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\desktop.ini
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c:\documents and settings\administrator\templates\cache\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\temp.db
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c:\documents and settings\administrator\templates\cache\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\tmp.db
Spreads via…
Removable drives
Worm:AutoIt/Autorun.U may create the following files on targeted drives when spreading:
- <targeted drive>:\thumbs.db
- <targeted drive>:\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\desktop.ini
- <targeted drive>:\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\temp.db
- <targeted drive>:\$recycle.bin\{5f229c11-5039-40e4-8537-6950bb1c9ecc}\tmp.db
It also places an autorun.inf file in the root directory of the targeted drive. Such autorun.inf files contain execution instructions for the operating system, so that when the removable drive is accessed from another computer supporting the Autorun feature, the malware is launched automatically.
Note: This worm was observed to write an executable and create an autorun.inf file on a targeted drive in our automated testing environment. This is particularly common malware behavior, generally utilized in order to spread malware from computer to computer.
It should also be noted that autorun.inf files on their own are not necessarily a sign of infection, as they are used by legitimate programs and installation CDs.
Payload
Terminates processes
Worm:AutoIt/Autorun.U terminates a list of specified processes, including those related to particular security applications, should they be running on an affected computer. Worm:AutoIt/Autorun.U attempts to terminate the following processes (for example):
Note: This list of processes was compiled after observing this behavior in our analysis systems. This list should serve as an example of this behavior only as it may not prove exhaustive on every affected system.
Modifies system settings
The malware modifies the affected computer system's settings by making the following changes to the registry:
- The malware disables the system utility Task Manager by making the following registry modification:
Adds value: "DisableTaskMgr"
With data: "1"
To subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System
- The malware ensures that Internet Explorer starts in online mode by making the following registry modification:
Adds value: "GlobalUserOffline"
With data: "0"
To subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- The malware removes the Folder Options item from all Explorer menus and the Control Panel by making the following registry modification:
Adds value: "NoFolderOptions"
With data: "1"
To subkey: HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer
Note: Removing access to these options may hinder the affected user's ability to detect and remove malware.
Contacts remote hosts
The malware may contact the following remote hosts using port 80:
- https.ath.cx
- neothedm.isa-geek.org
Commonly, malware may contact a remote host for the following purposes:
- To confirm Internet connectivity
- To report a new infection to its author
- To receive configuration or other data
- To download and execute arbitrary files (including updates or additional malware)
- To receive instruction from a remote attacker
- To upload data taken from the affected computer
This malware description was produced and published using our automated analysis system's examination of file SHA1 c85c8037642a0315c13dfcec8754a89f2c448f02.
