WORM_STEKCT.EVL

It uses several instant messaging applications and a social networking site to spread. The instant message it sends is a link that downloads a copy of itself.

It terminates processes or services that are mostly related to anti-malware programs. It also deletes the files that are related to the processes or services it terminates. It does the said routine to keep itself running on the affected system.

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 connects to a website to send and receive information.

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.

It may be downloaded from the following remote sites:

• http://bit.ly/K8sluf?{random}

Installation

This worm drops the following copies of itself into the affected system:

• %Windows%\iqs.exe

(Note: %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_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Microsoft Firevall Engine = "%Windows%\iqs.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Microsoft Firevall Engine = "%Windows%\iqs.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Terminal Server\
Install\Software\Microsoft\
Windows\CurrentVersion\Run
Microsoft Firevall Engine = "%Windows%\iqs.exe"

Other System Modifications

This worm adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Windows%\iqs.exe = "%Windows%\iqs.exe:*:Enabled:Microsoft Firevall Engine"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Windows%\iqs.exe = "%Windows%\iqs.exe:*:Enabled:MSN Messenger"

Propagation

This worm sends the following messages via instant-messaging (IM) applications:

http://bit.ly/K8sluf?{random} - also detected as WORM_STEKCT.EVL

It targets the following social networking site(s):

• Facebook

It sends messages that contain links to sites hosting remote copies of itself using the following instant-messaging (IM) applications:

• AIM
• Google Talk
• ICQ
• MSN
• Yahoo! Messenger

Backdoor Routine

This worm connects to the following websites to send and receive information:

• {BLOCKED}.{BLOCKED}.228.202
• news.{BLOCKED}dio.net
• safe.{BLOCKED}dio.net

Process Termination

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

• AntiVirService
• AviraUpgradeService
• MSASCui.exe
• MsMpEng.exe
• MsMpSvc
• WinDefend
• YahooAUService
• YahooAUService.exe
• avgnt.exe
• avp
• avp.exe
• egui.exe
• ekrn
• ekrn.exe
• kavsvc.exe
• msseces.exe
• wuauserv

NOTES:

This worm deletes the files related to the terminated running processes.