Analysis by: Khristian Joseph Morales

ALIASES:

Worm:BAT/Autorun.A (MICROSOFT)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Canal de infección Downloaded from the Internet, Dropped by other malware

This Worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

Tamaño del archivo 2,872 bytes
Tipo de archivo BAT
Residente en memoria Yes
Fecha de recepción de las muestras iniciales 11 Nov 2021
Carga útil Drops files

Arrival Details

This Worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Worm drops the following files:

  • {Malware Path}\sleep.vbe
  • %Windows%\{Malware Name}.bat
  • %Windows%\{Malware Name}.vbe
  • %Windows%\sleep.vbe
  • %Windows%\inf.tem
  • %Windows%\uishere-1.txt
  • {Drive Letter}\autorun.inf
  • {Drive Letter}\{Malware Name}.vbe
  • {Drive Letter}\{Malware Name}.bat

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

It adds the following processes:

  • attrib sleep.vbe +a +s +r +h
  • attrib "{Malware Path}\{Malware Name}.bat" -s -h
  • attrib "{Malware Path}\{Malware Name}.bat" +s +h
  • attrib "%Windows%\{Malware Name}.bat" +s +h
  • reg add HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run /v vbe /t REG_SZ /d "%Windows%\{Malware Name}.vbe" /f
  • %System%\WScript.exe "%Windows%\{Malware Name}.vbe"
  • cmd /c ""%Windows%\{Malware Name}.bat" /start"
  • attrib {Drive Letter}\autorun.inf +a +s +r +h
  • attrib "{Drive Letter}\{Malware Name}.vbe" +a +s +r +h
  • attrib "%Windows%\{Malware Name}.bat" -s -h
  • attrib "{Drive Letter}\{Malware Name}.bat" +s +h
  • attrib "U盘病毒分析Beta3" -s -h
  • attrib "U盘病毒分析Beta3" +s +h
  • attrib "{Drive Letter}\U盘病毒分析Beta3" +s +h
  • attrib {Drive Letter}\{Current Day} {current date}.sk +a +s +r +h
  • %System%\WScript.exe "%Windows%\sleep.vbe"
  • fc "{Drive Letter}\autorun.inf" inf.tem

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It creates the following folders:

  • {Drive Letter}\{Current Day}

Autostart Technique

This Worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
vbe = %Windows%\{Malware Name}.vbe

  SOLUTION

Motor de exploración mínimo 9.800
Primer archivo de patrones de VSAPI 17.186.05
Primera fecha de publicación de patrones de VSAPI 11 Nov 2021
Versión de patrones OPR de VSAPI 17.187.00
Fecha de publicación de patrones OPR de VSAPI 12 Nov 2021

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 2

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • vbe = %Windows%\{Malware Name}.vbe

Step 5

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • {Malware Path}\sleep.vbe
  • %Windows%\{Malware Name}.bat
  • %Windows%\{Malware Name}.vbe
  • %Windows%\sleep.vbe
  • %Windows%\inf.tem
  • %Windows%\uishere-1.txt
  • {Drive Letter}\autorun.inf
  • {Drive Letter}\{Malware Name}.vbe
  • {Drive Letter}\{Malware Name}.bat

Step 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • {Drive Letter}\{Current Day}

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Worm.BAT.USIGON.A. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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