Welinf is a virus that infects web files. Once executed, it secretly installs itself to the system and starts searching all local drives for .vbs, .htm and .html files. The parasite infects all files it finds with a malicious Visual Basic script. Welinf can also act as a backdoor providing the attacker with unauthorized remote access to the compromised computer. It allows the intruder to download and upload files, manage the file system, terminate running processes, log user keystrokes, take screenshots and restart the computer. The virus is able to avoid detection. It runs on every Windows startup.