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WORM_AUTORUN.ASM

October 08, 2012
 ALIASES:

Symantec: W32.SillyFDC; Microsoft: Worm:Win32/Orbina!rts; Kaspersky: Worm.Win32.AutoRun.avjm

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Copies itself in all available physical drives, Propagates via removable drives

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.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

212,992 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

15 Aug 2008

Payload:

Connects to URLs/Ips

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:

  • %Windows%\{Malware File Name}.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

It drops the following non-malicious file:

  • %Windows%\delautorun.ini

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • DELAUTORUN

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
DelAutorun = "%Windows%\{Malware File Name}.exe"

Propagation

This worm creates the following folder in all physical and removable drives:

  • Autorun.inf

Other Details

This worm connects to the following possibly malicious URL:

  • http://{BLOCKED}yes.scu.edu.cn

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

5.480.02

FIRST VSAPI PATTERN DATE:

15 Aug 2008

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Terminate a process file/s detected as WORM_AUTORUN.ASM

[ Learn More ]

*Note: If the detected file/s is/are not displayed in theWindows Task Manager, continue doing the next steps.

Step 3

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
    • DelAutorun = "%Windows%\{Malware File Name}.exe"

Step 4

Search and delete this file

[ Learn More ]
There may be some component 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. %Windows%\delautorun.ini

Step 5

Search and delete this folder

[ 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. Autorun.inf

Step 6

Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.ASM. 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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