http://www.sophos.com/virusinfo/anal...yusufalia.html
Arabic Trojan Blocks Erotic Websites
A new trojan called Yusufali-A wants to prevent users of infected Windows computers to visit pornographic websites. It checks the address bar of the active window and minimizes it as soon as the terms "sex", "teen", or "xx" are contained in the URL. Additionally a pop-up window is shown on the screen with a partially arabic partially english message (quotation of the 47th sura of the quran).
Included in the message is a countdown timer. If the browser window in question is not closed the trojan repeats messages periodically. It includes two further messages. One is completely in Arabic script. The last message includes the text "For Exit Click Here". If the mouse is moved into the window the message changes. Vertical bars and the text "OH! NO i'm in the Cage" appear. It is no longer possible to move the mouse pointer out of this window. The keyboard remains usable. The three buttons that are offered log out the current user.
The trojan does not contain further damage routines.
(source heise.de)