Yerg, when first run, launches a fake Microsoft Paint application. When this application is run, the worm infects the system and infects many files that you run. On the 18th of any month, the virus's payload activates. When the virus is run again, it displays a message: "W32.UFO... The Truth is out there W32.UFO .. The ALiens are Among us Flying around the night sky in their UFO Snatching people up, Shoving things inside there dong the short little guys with the big black eyes from a galacy far away and now the UFOs are on your PC!!! many of them, is UFO INvasion W32.UFO"