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Worm:Win32/Nuqel.BH

First posted on 05 June 2019.
Source: Microsoft

Aliases :

Worm:Win32/Nuqel.BH is also known as WORM_SOHANAD.DX, Worm.Win32.AutoRun.bchg, W32/Sohana-AO, W32.Imaut!gen1.

Explanation :

Worm:Win32/Nuqel.BH is a member of Win32/Nuqel - a family of worms that may spread via removable or network drives and particular messenger applications. It may also modify a number of system settings to facilitate its actions on an affected computer, and contact a remote host. Installation When executed, Worm:Win32/Nuqel.BH copies itself to the following locations:

%windir%sscvihost.exe lastclnnn.exe sscvihost.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:windowssystem32sscvihost.exe"
To subkey: HKCUSoftwareMicrosoftwindowscurrentversion
un Adds value: "Shell"
With data: "explorer.exe sscvihost.exe"
To subkey: HKLMSOFTWAREMicrosoftWindows NTCurrentVersionWinlogon The malware creates the following files on an affected computer:
autorun.ini - detected as Worm:Win32/Autorun!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 lastclnnn.exe Spreads via… Variants of the Win32/Nuqel family may use a number of different methods in order to spread to other computers.
Windows Live Messenger
Win32/Nuqel may spread using a number of different messaging applications, including Yahoo Messenger, AIM, Windows Messenger and Google Talk. It sends a message to all of the infected user's contacts with a link to a copy of itself.

Network shares
Some variants of Win32/Nuqel also try to spread through network shares by querying the following registry entry and copying themselves to any shared folders specified by this entry: HKCUSoftwareMicrosoftWindowsCurrentVersionExplorerWorkgroupCrawlerShares Removable drives Worm:Win32/Nuqel.BH 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:sscvihost.exe Payload Terminates processes Worm:Win32/Nuqel.BH 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 disables the system utility Task Manager by making the following registry modification:

Adds value: "DisableTaskMgr"
With data: "1"
To subkey: HKCUSoftwareMicrosoftWindowsCurrentVersionPoliciesSystem 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 removes the Folder Options item from all Explorer menus and the Control Panel by making the following registry modification:

Adds value: "NoFolderOptions"
With data: "1"
To subkey: HKCUSOFTWAREMicrosoftWindowsCurrentVersionPoliciesExplorer

Note: Removing access to these options may hinder the affected user's ability to detect and remove malware. 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 Contacts remote hosts The malware may contact the following remote hosts using port 80:

setting3.9999mb.comsetting3.yeahost.comwww.freewebs.com
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 733687fcfe18eec201eef28f1006a48c572419d4.

Last update 05 June 2019

 

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