RUNDLL.EXE

File Behavior

RUNDLL.EXE has been seen to perform the following behavior:

• The Process is packed and/or encrypted using a software packing process
• Executes a Process
• Writes to another Process's Virtual Memory (Process Hijacking)
• Uses DNS to retrieve the IP address for web sites
• The Process is polymorphic and can change its structure
• Includes file creation code which could be used to test for interception by security products
• Enables an In Process Object/Server - Common with DLL Injections
• Adds a Registry Key (RUN) to auto start Programs on system start up
• The process hooks code into all running processes which could allow it to take control of the system or record keyboard input, mouse activity and screen contents
• Registers a Dynamic Link Library File
• Can communicate with other computer systems using HTTP protocols
• This Process Deletes Other Processes From Disk
• This Process Contains User Mode Rootkit Functionality and can hide itself from the running process list
• Creates system tray popups, messages, errors and security warnings
• Found on infected systems and resists interrogation by security products
• Injects code into other processes
• Copies files
• Modifies firewall settings, without user permission so it is not blocked from accessing the Internet
• This process creates other processes on disk
• Performs DNS look ups to resolve URL IP addresses
• Uses Instant Messaging to communicate without the user's knowledge
• Uses embeded Instant Message Channel Settings
• Changes the Internet Explorer Home Page Settings

RUNDLL.EXE has been the subject of the following behavior:

• Added as a Registry auto start to load Program on Boot up
• Executed as a Process
• Created as a process on disk
• Has code inserted into its Virtual Memory space by other programs
• Copied to multiple locations on the system
• Registered as a Dynamic Link Library File
• The process is hooked into all running processes which could allow it to take control of the system or record keyboard input, mouse activity and screen contents
• Terminated as a Process
• Deleted as a process from disk