Modified by: Anthony Joe Melgarejo

ALIASES:

Worm:Win32/SillyShareCopy.gen (Microsoft), Win32/AutoRun.Autoit.CW worm (NOD32), Trojan-Downloader.Autoit.gen (VBA32), Trojan.Agent.ASAM (Bitdefender)

 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

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.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size: 771,072 bytes
File Type: EXE
File Compression: AutoIt
Memory Resident: Yes
Initial Samples Received Date: 05 Oct 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:

  • %Program Files%\avupdate.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

It drops the following files:

  • %Program Files%\run.ini - detected as TROJ_AUTOINI.CXC

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

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
Anti-Virus Update = "%Program Files%\avupdate.exe"

Other System Modifications

This worm adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft
C0d3R = "MADE IN INDIA.@AzUtRuM@"

HKEY_CURRENT_USER\Software\Microsoft\
C0d3R
C0d3R__INFO = "{message}"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = "1"

(Note: The default value data of the said registry entry is 0.)

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • {drive letter}:\Love-Story.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[Autorun]
useautoplay=1
Open=Love-Story.exe
Shellexecute=Love-Story.exe
Shell\open=Open
Shell\open\command=Love-Story.exe
Shell\Explore=Explore
Explore=Love-Story.exe
Shell\Explore\command=Love-Story.exe

Process Termination

This worm terminates the following processes if found running in the affected system's memory:

  • procdisp.exe
  • sample.exe
  • avguard.exe
  • setup.exe
  • rstrui.exe
  • taskkill.exe
  • mmc.exe
  • SCANNER.exe
  • ONLNSVC.exe
  • QUICKUP.exe
  • UPSCHD.exe
  • SCANNER.exe
  • zvmonNT.exe
  • zvregmon.exe
  • Update NP2005.exe

It terminates processes or services that contain any of the following strings if found running in the affected system's memory:

  • System Configuration
  • Registry Editor
  • Windows Task Manager
  • [CLASS:ConsoleWindowClass]

Download Routine

This worm accesses the following websites to download files:

  • http://www.avira.com - non-malicious URL

It saves the files it downloads using the following names:

  • %System Root%\av.sys - non-malicious file which contains the source code of said webpage

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

NOTES:
It searches for folders in all removable drives then copies itself inside the folder as {folder name}-Readme.exe

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.442.02
FIRST VSAPI PATTERN DATE: 05 Oct 2012
VSAPI OPR PATTERN File: 9.443.00
VSAPI OPR PATTERN Date: 06 Oct 2012

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

Remove malware files dropped/downloaded by WORM_UTOTI.CXC

    • TROJ_AUTOINI.CXC

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
    • Anti-Virus Update = %Program Files%\avupdate.exe
  • In HKEY_CURRENT_USER\Software\Microsoft
    • C0d3R = MADE IN INDIA.@AzUtRuM@
  • In HKEY_CURRENT_USER\Software\Microsoft\C0d3R
    • C0d3R__INFO = {message}

Step 5

Restore this modified 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\Explorer\Advanced\Folder\Hidden\SHOWALL
    • From: CheckedValue = "0"
      To: CheckedValue = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: HideFileExt = "1"
      To: HideFileExt = "0"

Step 6

Search and delete AUTORUN.INF files created by WORM_UTOTI.CXC that contain these strings

[ Learn More ]
[Autorun]
useautoplay=1
Open=Love-Story.exe
Shellexecute=Love-Story.exe
Shell\open=Open
Shell\open\command=Love-Story.exe
Shell\Explore=Explore
Explore=Love-Story.exe
Shell\Explore\command=Love-Story.exe

Step 7

Search and delete these files

[ 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.
  • {drive letter}:\Love-Story.exe
  • {drive letter}:\{folder name}\{folder name}-Readme.exe

Step 8

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