Worm:Win32/Autorun.ABW

Worm:Win32/Autorun.ABW 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.

When executed, Worm:Win32/Autorun.ABW copies itself to c:\recycler\s-1-5-21-2777772377-2664503705-086151845-6504\rundll32.exe.

The malware modifies the following registry entries to ensure that its copy executes at each Windows start:

Adds value: "Taskman"
With data: "c:\recycler\s-1-5-21-2777772377-2664503705-086151845-6504\rundll32.exe"
To subkey: HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

The malware creates the following files on an affected computer:

The malware utilizes code injection in order to hinder detection and removal. When Worm:Win32/Autorun.ABW executes, it may inject code into running processes, including the following, for example:

Worm:Win32/Autorun.ABW 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.

This malware description was produced and published using our automated analysis system's examination of file SHA1 9bdd73b2f19dc6a063dfe9d6f906b637500e1c64.