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You have been re-routed to the Worm:Win32/Cridex.B write up because Worm%3aWin32%2fCridex.B has been renamed to Worm:Win32/Cridex.B
 

Worm:Win32/Cridex.B


Worm:Win32/Cridex.B 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.


What to do now

To detect and remove this threat and other malicious software that may have been installed in your computer, run a full-system scan with an up-to-date antivirus product such as the following: For more information about using antivirus software, see http://www.microsoft.com/windows/antivirus-partners/.

Threat behavior

Worm:Win32/Cridex.B 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/Cridex.B copies itself to c:\documents and settings\administrator\application data\mslivesvc.exe.

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

Adds value: "mslivesvc.exe"
With data: "c:\documents and settings\administrator\application data\mslivesvc.exe"
To subkey: HKCU\Software\Microsoft\windows\currentversion\run

The malware creates the following files on an affected computer:

  • c:\documents and settings\administrator\local settings\temp\pos7.tmp.bat

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

  • cmd.exe
  • explorer.exe
  • rfwmain.exe

Payload
Modifies system settings
Worm:Win32/Cridex.B 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


Contacts remote host
The malware may contact a remote host at qjkakmwe22.ru using port 80. Commonly, malware may contact a remote host for the following purposes:
  • 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 c21414a64a2b8188ad849dfc5b5ab443680e76de.

Symptoms

System changes
The following system changes may indicate the presence of this malware:

  • The presence of the following files:

  • c:\documents and settings\administrator\application data\mslivesvc.exe
    c:\documents and settings\administrator\local settings\temp\pos7.tmp.bat

  • The presence of the following registry modifications:
  • Adds value: "mslivesvc.exe"
    With data: "c:\documents and settings\administrator\application data\mslivesvc.exe"
    To subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Run

    Adds value: "GlobalUserOffline"
    With data: "0"
    To subkey: HKCU\Software\Windows\CurrentVersion\Internet Settings


Prevention


Alert level: Severe
First detected by definition: 1.113.32.0
Latest detected by definition: 1.183.765.0 and higher
First detected on: Sep 22, 2011
This entry was first published on: Sep 29, 2011
This entry was updated on: Sep 30, 2011

This threat is also detected as:
  • PWS-Spyeye.de (McAfee)