Worm:Win32/Autorun.XEY 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:Win32/Autorun.XEY copies itself to the following locations:
- %windir%\system3_.exe
- <system folder>\system3_.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: "Yahoo Messengger"
With data: "c:\windows\system32\system3_.exe"
To subkey: HKCU\Software\Microsoft\windows\currentversion\run
Adds value: "Shell"
With data: "explorer.exe system3_.exe"
To subkey: HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
The malware creates the following files on an affected computer:
The malware attempts to create a scheduled Windows task that runs the worm at 09:00 am every day of the week, by running the following Windows shell command instruction:
cmd.exe /C AT /delete /yes
cmd.exe /C AT 09:00 /interactive /EVERY:m,t,w,th,f,s,su <system folder>\system3_.exe
Spreads via…
Removable and network drives
Worm:Win32/Autorun.XEY may copy itself to network and/or removable drives. It may also place 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 network and/or removable drive is accessed from another computer supporting the Autorun feature, the malware is launched automatically. 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.
Note: this worm was not observed to write an executable or create an autorun.inf file on a targeted drive in our automated testing environment. This may be because it does not begin spreading immediately, or because it may need to be commanded to spread from a remote source.
Payload
Modifies system settings
Worm:Win32/Autorun.XEY 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.
- The malware overrides the defined timeout period/value, resulting in scheduled tasks not being stopped after a timeout period; it does this by making the following registry modification:
Adds value: "AtTaskMaxHours"
With data: "0"
To subkey: HKLM\SYSTEM\CurrentControlSet\Services\Schedule
Modifies browser settings
The malware changes the start page for Internet Explorer to
http://www.mydreamworld.50webs.com by making the following registry modification:
Adds value:
"Start Page" With data:
"http://www.mydreamworld.50webs.com"To subkey:
HKCU\Software\Microsoft\Internet Explorer\Main
Contacts remote hosts
The malware may contact the following remote hosts using port 80:
- h1.ripway.com
- www.balu000.0catch.com
- www.balu001.0catch.com
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 9eac0ba49e218a48e2e41843485c5ac9b184f57e.