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Backdoor:Win32/Zegost.DQ

First posted on 06 July 2015.
Source: Microsoft

Aliases :

There are no other names known for Backdoor:Win32/Zegost.DQ.

Explanation :

Threat behavior

Installation
This threat can create files on your PC, including:

• %ProgramFiles%\microsoft qiugkw\sukemck.exe

It modifies the registry so that it runs each time you start your PC. For example:

In subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run Sets value: "Ddmaud jfytbwkg"
With data: "%ProgramFiles%\microsoft qiugkw\sukemck.exe"

The malware uses code injection to make it harder to detect and remove. It can inject code into running processes.



Payload


Allows backdoor access and control

This threat can give a malicious hacker access and control of your PC. They can then perform a number of different actions, such as:

• Deleting files
• Downloading and running files
• Logging your keystrokes or stealing your sensitive data
• Modifying your system settings
• Running or stopping applications
• Spreading malware to other PCs
• Uploading files

Connects to a remote host

We have seen this threat connect to a remote host, including:

• yuhen520.f3322.net using port 53
• ilo.brenz.pl using port 53
• ant.trenz.pl using port 53
• ykcquf.com using port 53
• ciainb.com using port 53
• ztrjcs.com using port 53

Malware can connect to a remote host to do any of the following:

• Check for an Internet connection
• Download and run files (including updates or other malware)
• Report a new infection to its author
• Receive configuration or other data
• Receive instructions from a malicious hacker
• Search for your PC location
• Upload information taken from your PC
• Validate a digital certificate

It can stop some processes from running on your PC, including:

• ashdisp.exe
• avcenter.exe
• egui.exe
• knsdtray.exe
• kvmonxp.exe
• kxetray.exe
• mcshield.exe
• ravmond.exe
• rundll32.exe
• tmbmsrv.exe

Bypasses firewall



This threat tries to bypass your firewall by modifying the registry. For example:

HKLM\system\currentcontrolset\services\sharedaccess\parameters\firewallpolicy

You might need to restore your Windows Firewall settings.



Additional information

Creates a mutex

This threat can create one or more mutexes on your PC. For example:

• c:!windows!system32!config!systemprofile!appdata!local!microsoft!windows!history!history.ie5!
• c:!windows!system32!config!systemprofile!appdata!local!microsoft!windows!temporary internet files!content.ie5!
• c:!windows!system32!config!systemprofile!appdata!roaming!microsoft!windows!cookies!

It might use this mutex as an infection marker to prevent more than one copy of the threat running on your PC.



This malware description was published using automated analysis of file SHA1 d8dc89f8203a5c53a22693f13ca735f2da9d1f98.

Symptoms

The following can indicate that you have this threat on your PC:

• You see a file similar to:
  • %ProgramFiles%\microsoft qiugkw\sukemck.exe

• You see registry modifications such as:
  
  • In subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    Sets value: "Ddmaud jfytbwkg"
    With data: "%ProgramFiles%\microsoft qiugkw\sukemck.exe"
    
    
  • In subkey: HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    Sets value: "\winlogon.exe"
    With data: "\winlogon.exe:*:enabled:@shell32.dll,-1"
    
    
  • In subkey: HKLM\SYSTEM\CurrentControlSet\Services\Wsfbxu gveivbdh
    Sets value: "ConnectGroup"
    With data: "ä¬Ã¨Ã¯·Ã¶Ã—é"
    
    
  • In subkey: HKLM\SYSTEM\CurrentControlSet\Services\Wsfbxu gveivbdh
    Sets value: "MarkTime"
    With data: "2009-12-11 05:36"

• You see the following mutex:
  • c:!windows!system32!config!systemprofile!appdata!local!microsoft!windows!history!history.ie5!
  • c:!windows!system32!config!systemprofile!appdata!local!microsoft!windows!temporary internet files!content.ie5!
  • c:!windows!system32!config!systemprofile!appdata!roaming!microsoft!windows!cookies!

Last update 06 July 2015

 

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