Analysis by: Sabrina Lei Sioting
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This worm arrives by connecting affected removable drives to a system. It 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 749,067 bytes
Tipo de archivo EXE
Residente en memoria No
Fecha de recepción de las muestras iniciales 11 Apr 2012

Arrival Details

This worm arrives by connecting affected removable drives to a system.

It 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%\chrome9.exe
  • %System%\chrome9.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It drops the following files:

  • %User Profile%\Desktop\Search.lnk
  • %User Profile%\Favorites\Sioril.lnk
  • %User Profile%\My Documents\Search bar.lnk
  • %User Profile%\Start Menu\Programs\Startup\Search bar.lnk
  • %Windows%\Tasks\At1.job

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Yahoo Messengger = "%System%\chrome9.exe"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "Explorer.exe chrome9.exe"

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

Other System Modifications

This worm modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = "http://www.chrome10.com/"

(Note: The default value data of the said registry entry is {default homepage}.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Default_Page_URL = "http://www.chrome10.com/"

(Note: The default value data of the said registry entry is {default homepage}.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Default_Search_URL = "http://www.chrome10.com/"

(Note: The default value data of the said registry entry is {default searchpage}.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Search Page = "http://www.chrome10.com/"

(Note: The default value data of the said registry entry is {default searchpage}.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Start Page = "http://www.chrome10.com/"

(Note: The default value data of the said registry entry is {default homepage}.)

Propagation

This worm searches for folders in all physical and removable drives then drops copies of itself inside the folder as {folder name}.EXE.

It drops the following copies of itself in all physical and removable drives:

  • chrome9.exe
  • New Folder.exe