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Worm:Win32/Vobfus.F

First posted on 18 June 2019.
Source: Microsoft

Aliases :

Worm:Win32/Vobfus.F is also known as Trojan.VB.Chinky.F, Win32.HLLW.Autoruner.8325, Virus.Worm.Win32.VBNA, Worm.Win32.VBNA.jdn, W32/VBNA.worm, W32/Autorun-ASF, W32.Changeup, Worm.VBNA.Gen.

Explanation :

Worm:Win32/Vobfus.F is a worm that spreads to removable and remote drives, changes Windows settings, and may download other malware. Installation When run, the worm drops a copy of itself into the logged-on user's profile directory as a random character string as in this example:  %USERPROFILE%gilen.exe  The registry is modified to run the dropped copy at each Windows start, as in this example: Adds value: "gilen"With data: "%USERPROFILE%gilen.exe"To subkey: HKCUSoftwareMicrosoftWindowsCurrentVersionRun Spreads Via… Removable drivesWorm:Win32/Vobfus.F enumerates removable drives and drops copies of the worm executable (for example, "gilen.exe" and "gilen.scr") under the root folder of each removable drive:  gilen.exe gilen.scr The worm then writes an autorun configuration file named "autorun.inf" pointing to the worm copy with ".exe" file extension. When the drive is accessed from a machine supporting the Autorun feature, the worm is launched automatically.  Remote drivesWorm:Win32/Vobfus.F drops copies of the worm executable (for example, "gilen.exe" and "gilen.scr") under the root folder of each writeable remote drive:  gilen.exe gilen.scr  The worm also creates shortcuts under the root directory on remote drives that have the same name as existing folders in the root directory, f or example: 
ew folder.lnk passwords.lnk documents.lnk pictures.lnk music.lnk
video.lnk The shortcut links to the dropped worm executable with ".scr" file extension. Once the users opens the link, the worm copy executes. Payload Modifies Windows settingsThe worm disables viewing of Windows system files with attributes "hidden" by modifying the following registry data: Modifies value: "ShowSuperHidden"With data: "0"To subkey: HKCUSoftwareMicrosoftWindowsCurrentersionExplorerAdvanced  Downloads other malwareThe worm also attempts connecting to a remote host "ns.theimageparlour.net" using TCP port 8000 to download other malicious binaries.  Analysis by Aaron Putnam

Last update 18 June 2019

 

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