ALIASES:

Worm:Win32/Autorun.ABP (Microsoft); W32/Autorun.worm.zv (McAfee); Virus.Win32.Renamer.l (Kaspersky); Worm.Win32.Autorun.fqc (V) (Sunbelt); Worm.Generic.251957 (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

File Size: 258,048 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 02 May 2012

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 copies of itself into the affected system:

  • %System%\windows.exe
  • %System%\csrss.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

It creates the following folders:

  • %System Root%\RECYCLER
  • %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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
{malware path and file name} = "{malware path and file name}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
%System%\csrss.exe = "%System%\csrss.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{28ABC5C0-4FCB-11CF-AAX5-81CX1C635612}
StubPath = "%System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\smartmgr.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
%System%\windows.exe = "%System%\windows.exe"

Other System Modifications

This worm adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{28ABC5C0-4FCB-11CF-AAX5-81CX1C635612}

Dropping Routine

This worm drops the following files:

  • %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\Desktop.ini
  • %System Root%\Documents and Settings.exe
  • 54037f8b5935Program Files.exe
  • 54037f8b5935RECYCLER.exe
  • 54037f8b5935System Volume Information.exe
  • 54037f8b5935WINDOWS.exe
  • %System%\windows.exe
  • %System%\csrss.exe
  • %Windows%\windowsxp.exe
  • %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\smartmgr.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.200

Step 1

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

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry key

[ 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\Active Setup\Installed Components
    • {28ABC5C0-4FCB-11CF-AAX5-81CX1C635612}

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
    • {malware path and file name} = "{malware path and file name}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • %System%\csrss.exe = "%System%\csrss.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{28ABC5C0-4FCB-11CF-AAX5-81CX1C635612}
    • StubPath = "%System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\smartmgr.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • %System%\windows.exe = "%System%\windows.exe"

Step 5

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\Desktop.ini
  • %System Root%\Documents and Settings.exe
  • 54037f8b5935Program Files.exe
  • 54037f8b5935RECYCLER.exe
  • 54037f8b5935System Volume Information.exe
  • 54037f8b5935WINDOWS.exe
  • %System%\windows.exe
  • %System%\csrss.exe
  • %Windows%\windowsxp.exe
  • %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\smartmgr.exe

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.
  • %System Root%\RECYCLER
  • %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_AUTORUN.SML. 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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