WORM_PHORPIEX.CII

This worm arrives via removable drives. It 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.

Arrival Details

This worm arrives via removable drives.

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 adds the following folders:

• %Application Data%\Microsoft-Driver-1-25-8784-4125-7572
• {Removable Drive}:\{random numbers}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It drops the following copies of itself into the affected system and executes them:

• %Application Data%\Microsoft-Driver-1-25-8784-4125-7572\winsvc.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

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
Microsoft® NSVTCR Driver = "%Application Data%\Microsoft-Driver-1-25-8784-4125-7572\winsvc.exe"

Other System Modifications

This worm creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Application Data%\Microsoft-Driver-1-25-8784-4125-7572\winsvc.exe = "%Application Data%\Microsoft-Driver-1-25-8784-4125-7572\winsvc.exe:*:Enabled:Microsoft® NSVTCR Driver"

Propagation

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

• {Removable Drive}:\wincdrs32.exe
• {Removable Drive}:\{random numbers}\{Folder Names}.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]
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shellexecute=wincdrs32.exe
UseAutoPlay=1

NOTES:
This worm creates .LNK (shortcut) files pointing to the copy of WORM_PHORPIEX.CII named {Removable Drive}:\{random numbers}\{Folder Names}.exe. {Folder Names} are the folder names found at the root of the removable drive, if there are any. It then sets the attribute of the said folders to Hidden.