Win32.Worm.Prolaco.S is worm that is known to be generally associated with e-greeting cards. These cards are usually sent via email and the worm is hidden inside the zipped attachments. The worm also spreads via removable media devices, emails and peer to peer file sharing networks. The worm makes multiple copies of itself included a hidden copy of itself in the system folder. The worm also changes the registry entries. Prolaco also acts like a keylogger, capturing all keystrokes. It stores these captured keystrokes in a file named lsm.dll. The worm is transmitted via the memory space of browsers and therefore, it can easily bypass the windows firewall settings. It gives rise to numerous unwanted pop ups and downloads various unwanted files.