Websense has issued an alert warning that a Trojan, known as both Warezov and Stration, is spreading through the Skype network again (an earlier version initially attacked late in February). Typical instant messaging viruses are successful in spreading solely thanks to users" ignorance, and this time is no different: the Trojan is not taking advantage of a vulnerability in Skype, Websense noted. While the code itself is not self-propagating, when a user opens it, a message that says "Check up this," along with a URL to the Trojan (a file entitled file_01.exe) is sent to everyone in the user"s contact list. If the user runs the file, several other files are downloaded and run. The Trojan also opens a back door in the user"s computer, enabling a hacker to get into the machine.