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You have been re-routed to the Backdoor:Win32/Lybsus.B write up because Backdoor%3aWin32%2fLybsus.B has been renamed to Backdoor:Win32/Lybsus.B
 

Backdoor:Win32/Lybsus.B


Backdoor:Win32/Lybsus.B is a trojan that allows unauthorized access and control of an affected computer.


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

Backdoor:Win32/Lybsus.B is a trojan that allows unauthorized access and control of an affected computer.
Installation
When executed, Backdoor:Win32/Lybsus.B copies itself to %windir%\config.exe.

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

Adds value: "winlogon"
With data: "c:\windows\config.exe"
To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

The malware creates the following files on an affected computer:

  • c:\documents and settings\administrator\application data\1.bat
Payload
Allows backdoor access and control
Backdoor:Win32/Lybsus.B allows unauthorized access and control of an affected computer. An attacker can perform any number of different actions on an affected computer using Backdoor:Win32/Lybsus.B. This could include, but is not limited to, the following actions:

  • Download and execute arbitrary files
  • Upload files
  • Spread to other computers using various methods of propagation
  • Log keystrokes or steal sensitive data
  • Modify system settings
  • Run or terminate applications
  • Delete files

This malware description was produced and published using our automated analysis system's examination of file SHA1 d652cb33b7f366ddf942dc1f1ac23697baaa52a6.

Symptoms

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

  • The presence of the following files:

  • %windir%\config.exe
    c:\documents and settings\administrator\application data\1.bat

  • The presence of the following registry modifications:
  • Adds value: "winlogon"
    With data: "c:\windows\config.exe"
    To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run


Prevention


Alert level: Severe
First detected by definition: 1.139.1212.0
Latest detected by definition: 1.191.67.0 and higher
First detected on: Nov 02, 2012
This entry was first published on: Nov 05, 2012
This entry was updated on: Nov 13, 2012

This threat is also detected as:
  • Trojan.Win32.Agent.thyy (Kaspersky)
  • Trojan.ADH (Symantec)