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Worm:Win32/Esfury.A

First posted on 31 July 2010.
Source: SecurityHome

Aliases :

Worm:Win32/Esfury.A is also known as Trojan.Win32.VB.agsv (Kaspersky).

Explanation :

Worm:Win32/Esfury.A 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. Commonly, worms may spread directly by copying themselves to removable or network drives, or by attempting to exploit particular vulnerabilities on targeted computers. Worms also often attempt to spread via platforms that require user interaction in order to run. They may send themselves as an attachment to an email or an instant message, or send a link to a copy of themselves in the body of a message. In these cases the message needs to be convincing enough to encourage the victim to click on the link or attachment and run or download a copy of the worm.
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Worm:Win32/Esfury.A 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. Commonly, worms may spread directly by copying themselves to removable or network drives, or by attempting to exploit particular vulnerabilities on targeted computers. Worms also often attempt to spread via platforms that require user interaction in order to run. They may send themselves as an attachment to an email or an instant message, or send a link to a copy of themselves in the body of a message. In these cases the message needs to be convincing enough to encourage the victim to click on the link or attachment and run or download a copy of the worm. Installation When executed, Worm:Win32/Esfury.A copies itself to c:\documents and settings\administrator\administrator1\winlogon.exe.
The malware modifies the following registry entries to ensure that its copy executes at each Windows start:

Adds value: "NVIDIA Media Center Library"
With data: "c:\documents and settings\administrator\administrator1\winlogon.exe"
To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Adds value: "NVIDIA Media Center Library"
With data: "c:\documents and settings\administrator\administrator1\winlogon.exe"
To subkey: HKCU\Software\Microsoft\windows\currentversion\run
The malware creates the following files on an affected computer:

c:\documents and settings\administrator\administrator1\version.txt

c:\documents and settings\administrator\administrator1\winhelp32.exe

Spreads via€¦ Removable drives Worm:Win32/Esfury.A copies itself to the following locations on removable drives:

<targeted drive>:\drivesguideinfo\svchost.exe

<targeted drive>:\drivesguideinfo\s-1-9-01-3739977401-4444491267-600313374-9146\svchost.exe

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 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.
The malware may also create the following files on targeted drives when spreading:

<targeted drive>:\drivesguideinfo.lnk

<targeted drive>:\subst.lnk

<targeted drive>:\drivesguideinfo\s-1-9-01-3739977401-4444491267-600313374-9146\desktop.ini

Payload Contacts remote hosts Worm:Win32/Esfury.A may contact the following remote hosts using port 80:

0-0-0-0-1-0-0-1-1-0-0-0-1-0-0-1-0-1-1-0-0-1-1-1-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-7-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-0-0-1-0-0-1-1-0-0-0-1-0-0-1-0-1-1-0-0-1-1-1-1-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-15-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-0-0-1-1-1-0-0-1-0-0-1-1-1-0-0-0-0-1-1-0-1-1-1-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-23-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-0-0-1-1-1-0-1-1-1-0-0-1-1-0-1-0-1-1-0-0-1-0-0-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-24-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-0-1-0-0-1-1-0-0-0-1-0-0-1-0-1-1-0-0-1-1-1-1-1-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-31-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-0-1-0-1-1-0-1-0-1-0-0-1-1-0-0-1-0-1-0-1-1-0-1-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-37-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-0-1-1-0-0-0-0-1-1-1-0-0-0-0-0-0-0-1-1-0-1-0-0-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-40-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-0-1-1-0-1-0-1-1-0-1-0-0-1-0-0-1-1-1-0-1-0-0-0-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-44-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-0-1-1-1-1-0-1-1-1-1-1-1-1-0-1-0-0-1-0-0-0-1-1-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-51-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-0-1-1-1-1-1-1-0-0-1-0-1-1-1-0-0-1-0-1-0-0-0-0-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-52-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-1-0-0-0-1-1-1-1-0-0-0-0-1-1-0-1-0-0-0-1-0-1-1-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-59-0-0-0-0-0-0-0-0-0-0-0-0-0.info

0-1-0-0-1-0-0-0-1-0-1-1-0-1-1-1-1-0-1-1-1-0-0-0-1-1-1-1-1-1-1-.0-0-0-0-0-0-0-0-0-0-0-0-0-60-0-0-0-0-0-0-0-0-0-0-0-0-0.info

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 9E684440F4D5F3AFF05FF74497BF865AA676DC4C.

Last update 31 July 2010

 

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