Thu, 28 Sep 2000 Matrix. This worm is extremely prolific and spreads fast, which is why we issue this message. Matrix consists of three components: A Win32 infector, an e-mail worm, and a backdoor. An infection starts when attempting to open an attachment to e-mail, having one of the names listed below: README.TXT.pif I_wanna_see_YOU.TXT.pif MATRiX_Screen_Saver.SCR LOVE_LETTER_FOR_YOU.TXT.pif NEW_playboy_Screen_saver.SCR BILL_GATES_PIECE.JPG.pif TIAZINHA.JPG.pif FEITICEIRA_NUA.JPG.pif Geocities_Free_sites.TXT.pif NEW_NAPSTER_site.TXT.pif METALLICA_SONG.MP3.pif ANTI_CIH.EXE INTERNET_SECURITY_FORUM.DOC.pif ALANIS_Screen_Saver.SCR READER_DIGEST_LETTER.TXT.pif WIN_$100_NOW.DOC.pif IS_LINUX_GOOD_ENOUGH!.TXT.pif QI_TEST.EXE AVP_Updates.EXE SEICHO-NO-IE.EXE YOU_are_FAT!.TXT.pif FREE_xxx_sites.TXT.pif I_am_sorry.DOC.pif Me_nude.AVI.pif Sorry_about_yesterday.DOC.pif Protect_your_credit.HTML.pif JIMI_HMNDRIX.MP3.pif HANSON.SCR FUCKING_WITH_DOGS.SCR MATRiX_2_is_OUT.SCR zipped_files.EXE BLINK_182.MP3.pif Normally, the PIF extension won't show, and the user could be misled by the apparently "innocent" file extension, and open the attachment. Which will start the infection, and installation of the worm and backdoor. Matrix has no deliberate destructive payload. Yet its virus component is highly prolific and difficult to remove, once it got installed. Moreover, the backdoor that Matrix installs can be used in rather dangerous ways. InVircible users, all builds since the introduction of the Startup Apps Monitor, get warned of the installation of Matrix. Unfortunately, this doesn't suffice to prevent the virus component from infecting programs.