MSNworm.IN is a virus that spreads to other computers by copying its code to other files or programs.
It captures certain information entered or saved by the user, with the corresponding threat to privacy:
passwords saved by certain Windows services; keystrokes, in order to obtain information for accessing online banking services, passwords and other confidential information; email addresses.
It sends the gathered information to a remote user by any available means: email, FTP, etc.
- In the local network:
it generates a large amount of network activity and consumes bandwidth.
It reduces the security level of the computer:
it notifies the attacker that the computer has been compromised and is ready to be used maliciously; it awaits remote-control orders received through
IRC; it changes system permissions, decreasing the security level.
It uses stealth techniques to avoid being detected by the user:
- It injects itself in running processes.
- It modifies system permissions in order to hide itself.
MSNworm.IN uses the following propagation or distribution methods:
- Exploiting vulnerabilities with the intervention of the user: exploiting vulnerabilities in file formats or applications. To exploit them successfully it needs the intervention of the user: opening files, viewing malicious web pages, reading emails, etc.
- Via Internet, exploiting remote vulnerabilities: attacking random IP addresses, in which it tries to insert a copy of itself by exploiting one or more vulnerabilities.
- Instant messaging: it sends links pointing to a copy of itself to all users included in the infected user's contacts list.
- Computer networks (mapped drives): it creates copies of itself in mapped drives.
MSNworm.IN uses the following infection strategies:
- Resident: once it has been run, the virus goes memory resident and stops functions belonging to the operating system. Therefore, every time the operating system or an application tries to access any of these functions, the virus will activate and infect new files.