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Worm:Win32/Nuqel.AT

First posted on 09 June 2019.
Source: Microsoft

Aliases :

Worm:Win32/Nuqel.AT is also known as Worm.Win32.AutoIt.ru, W32.Imaut.CN.

Explanation :

Worm:Win32/Nuqel.AT 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/Nuqel.AT copies itself to the following locations:

%windir%sichost.exe sichost.exe
Note: refers to a variable location that is determined by the malware by querying the Operating System. The default installation location for the System folder for Windows 2000 and NT is C:WinntSystem32; and for XP, Vista, and 7 is C:WindowsSystem32.
The malware modifies the following registry entries to ensure that its copy executes at each Windows start:

Adds value: "Yahoo Messengger"
With data: "c:windowssystem32sichost.exe"
To subkey: HKCUSoftwareMicrosoftwindowscurrentversion
un
Adds value: "Shell"
With data: "explorer.exe sichost.exe"
To subkey: HKLMSOFTWAREMicrosoftWindows NTCurrentVersionWinlogon
The malware creates the following files on an affected computer:
autorun.ini - detected as Worm:Win32/Sohanad.AR!inf setting.ini
The malware attempts to create a scheduled Windows task that runs the worm at 09:00 am every day of the week, by running the following Windows shell command instruction:

cmd.exe /C AT /delete /yes
cmd.exe /C AT 09:00 /interactive /EVERY:m,t,w,th,f,s,su SICHOST.exe Spreads via… Removable drives Worm:Win32/Nuqel.AT copies itself to the following locations on removable drives:

:subst.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 drive 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:

:
ew folder.exe:sichost.exe Payload Terminates processes Worm:Win32/Nuqel.AT terminates the following processes should they be running on an affected computer:

cmd.exe
Modifies system settings The malware modifies the affected computer system's settings by making the following changes to the registry:

The malware ensures that Internet Explorer starts in online mode by making the following registry modification:

Adds value: "GlobalUserOffline"
With data: "0"
To subkey: HKCUSoftwareMicrosoftWindowsCurrentVersionInternet Settings

The malware overrides the defined timeout period/value, resulting in scheduled tasks not being stopped after a timeout period; it does this by making the following registry modification:

Adds value: "AtTaskMaxHours"
With data: "0"
To subkey: HKLMSYSTEMCurrentControlSetServicesSchedule
Modifies browser settings The malware changes the start page for Internet Explorer to http://www.blackcheta.blogspot.com/ by making the following registry modification:

Adds value: "Start Page"
With data: "http://www.blackcheta.blogspot.com/"
To subkey: HKCUSoftwareMicrosoftInternet ExplorerMain
Contacts remote hostThe malware may contact a remote host at lotusspring3.t35.com using port 80. Commonly, malware may contact a remote host for the following purposes:To report a new infection to its authorTo receive configuration or other dataTo download and execute arbitrary files (including updates or additional malware)To receive instruction from a remote attackerTo upload data taken from the affected computer
This malware description was produced and published using our automated analysis system's examination of file SHA1 7aafa5e31b43f1262cb2e9a974fd1d7804996526.

Last update 09 June 2019

 

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