WORM_OTOIT.DCS

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.

It executes commands from a remote malicious user, effectively compromising the affected system.

It deletes the initially executed copy of itself.

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

• %System%\csrcs.exe
• %System%\{random number}.exe

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

It drops the following files:

• %System%\autorun.inf

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

It drops the following non-malicious files:

• %User Temp%\suicide.bat - used to delete the initially executed copy. It deletes itself after successfully deleting the malware's initial copy
• {drive letter}:\{random filename} - empty file

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

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\policies\
Explorer\Run
csrcs = "%System%\csrcs.exe"

It modifies the following registry entry(ies) to enable its automatic execution at every system startup:

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

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

Other System Modifications

This worm adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
dreg = "{random}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
exp1 = "{random}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
fix = ""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
fix1 = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
ilop = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
GlobalUserOffline = "0"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
SuperHidden = "0"

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"

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

Propagation

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

• {drive letter}:\{random filename}.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:

;{garbage characters}
[AuTOrUn
;{garbage characters}
open={random filename}.exe
;{garbage characters}
shell\open\Command={random filename}.exe
;{garbage characters}
shell\open\Default=1
;{garbage characters}

Backdoor Routine

This worm executes the following commands from a remote malicious user:

• Download and execute files
• Manage files
• List active window titles
• List and terminate processes
• Query and manipulate registries
• Scan for IP addresses within the network
• Update copy of itself

It connects to the following URL(s) to send and receive commands from a remote malicious user:

• http://{BLOCKED}d.{BLOCKED}ster.com:5400/banner.gif
• http://{BLOCKED}rz.hm:4580/banner.gif
• http://{BLOCKED}u.{BLOCKED}atama.com:4700/banner.gif
• http://{BLOCKED}d.{BLOCKED}ster.com:5400/po.php
• http://{BLOCKED}.{BLOCKED}.19.236:4700/fruits.htm

Information Theft

This worm gathers the following data:

• IP address
• Language
• Computer information
• OS information
• User information
• Drive Information

Other Details

This worm connects to the following URL(s) to check for an Internet connection:

• http://www.doctorshadow.com

It connects to the following URL(s) to get the affected system's IP address:

• http://checkip.dyndns.org
• http://www.whatismyip.com/automation/n09230945.asp

It deletes the initially executed copy of itself