Windows 2003/XP/2000/NT/ME/98/95

MSNworm.CY is a worm that spreads by copying itself, without infecting other files.

It captures certain information entered or saved by the user, with the corresponding threat to privacy: keystrokes, in order to obtain information for accessing online banking services, passwords and other confidential information.

It reduces the security level of the computer: it awaits remote-control orders received through IRC.

It uses stealth techniques to avoid being detected by the user:

• It deletes the original file from which it was run once it is installed on the computer.

It uses several methods in order to avoid detection by antivirus companies:

• It terminates its own execution if it detects that it is being executed in a virtual machine environment, such as VMWare or VirtualPC.

MSNworm.CY 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.
• Peer-to-peer (P2P) file sharing programs: it makes copies of itself with enticing names in shared folders belonging to these programs. Other users of this type of networks then voluntarily download and run the infected files.
• Instant messaging: it sends links pointing to a copy of itself to all users included in the infected user's contacts list.