Nodelm.A is a backdoor that opens a TCP port, in order to carry out several actions, such as download and run files. These files can be of any nature, including malware.
Additionally, it ends processes and services belonging to several security tools, such as antivirus programs and firewalls, among others.
Nodelm.A does not spread automatically using its own means. It needs an attacking user's intervention in order to reach the affected computer. The means of transmission used include, among others, floppy disks, CD-ROMs, email messages with attached files, Internet downloads, FTP, IRC channels, peer-to-peer (P2P) file sharing networks, etc.